Thanks for the great post. As a disclaimer, I've been working as a contractor for the last 18 months or so supporting a major TV/Cable company's broadcast operations' embedded software for digital video, and years earlier I did work for IBM with digital video and cable set-top boxes, so the below may be biased in that sense.
One thing I might point out is that in Europe, even with TV, the sort of community life you describe is somewhat more intact. So, there is some sort of difference in the USA. TV is no doubt part of the change in our society. But there are other factors. One is the spread of the socially isolating automobile. Another is the movement of women into the paid exchange economy and away from the home-based gift economy (including less in-home child care), away from the subsistence economy of home production, and away from voluntary participating in local community-planned economy. Another is increasing material aspirations, including how larger homes with larger yards physically separate people more; see "Culture of Affluence: Psychological Costs of Material Wealth" by Suniya S. Luthar. The rising professionalization of so many activities has discouraged individuals helping each other (you are more likely now to see a psychologist instead of talk to your neighbor over the fence while putting up laundry, with the solution being prescription drugs instead of social change). Lengthening school days (and years with grad school) means less people are around regular communities. The rise of big box stores displacing locally-owned neighborhood stores is another factor. So is the loss of the family farm and the culture that produces. The reduction of unions in the USA and loss of long vacations and shorter working hours is probably another big factor making for less time to be neighborly. No doubt there are more factors as well due to technological and political changes.
Your post reminds me of a Simpson's episode where for some reason all the TVs stop working and the community immediately renews itself, families interact more, kids play outside, everyone is happier and healthier, and everyone acknowledges that, but as soon as the TVs start working again, people go right back to sitting in front of them. That too has a ring of truth to it. Why would that be? There is a book by Dierdre Barrett called "Supernormal Stimuli: How Primal Urges Overran Their Evolutionary Purpose". It suggests that humans, like all creatures, a wired to respond to certain things. In prehistoric times, these behaviors like responding to quick movements (might be a snake about to strike), or seeking out sweet things (like ripe berries), were adaptive and helped us survive. With modern technology, where quickly changing scenes on a video screen or piles of processed sugar are both easy to conjur up, these tendencies may be maladaptive. Paul Graham wrote an essay on "The Acceleration of Addictiveness", about many addictive things including drugs like cheap alcohol becoming bigger and bigger challenges. The book "The Pleasure Trap" makes a similar point, focusing mostly just on junk food. For food, it used to be that to get sweetness, you had to eat a lot of fruit which had fiber and phytonutrients which were essential to human health. Now you can just get obese on sugar, and get sick too, because you won't be eating the fiber or phytonutrients. The same is true now for interesting experiences. In the past, when TV did not exist, or when it had only a few channels with less programming (like when I was a child), then it was hard to overindulge in it. When you wanted to see people, you generally had to interact with real people in real families and real communities, which generally had other health benefits (maintaining healthy social connections). Or you might read a book. :-) Now you can be part of a TV "family" and get lots of excitement and laughs very easily, but you do not gain the real social connections from that time investment that could help you in other ways. That is an aspect of Neil Postman's book on TV: "Amusing Ourselves to Death". There is also a theme in "Brave New World", where people are controlled by pleasure, as opposed to in "1984" where they are controlled by pain.
Since humans are such visual creatures, and because visual input is more direct than auditory input from sounds or language which requires more inferences (including self-talk from reading), video is a fairly direct path into the brain. Young kids especially tend to be able to adjust their imagination of some fairy tale they heard read to them to what they can cope with (e.g. "Jack slew the giant with a sword"), but if they actually see that depicted graphically on a screen they may get nightmares for years. Radio and reading require much more work in terms of thought and imagination to process. So, some mental exercise and control is lost in watching video in that sense. And of course physical exercise is lost when sitting on a couch (as opposed to using a treadmill to watch video), as is exposure to sunlight when watching indoors (a vital nutrient to make Vitamin D in the skin, required by the immune system to work correctly). Video has also been historically expensive to produce, so the video we see in general is shaped by the most powerful interests in our society, as opposed to cheaper-to-produce interactions with neighbors or books which tent to reflect broader interests. The book, "The War Play Dilemma" talks about how deregulation of broadcast television around 1980 lead to a 24X7 experience of marketing to kids (e.g. superhero videos, toys, foods, and bed sheets) which the authors say has lead to a reduced, stylized, and extra-violent play repertoire in many boys. They have another book "So Sexy, So Soon" on what that has done to young girls.
Still, even for music, which used to mean community, digital audio on cheap players now means you can have music whenever you want, but the immediate community of musicians that listening to music used to imply is no longer there. So, music becomes another supernormal stimuli, missing in the social fiber and social nutrition it used to imply. Clay Skirky, in "Here Comes Everybody", also talks about TV as like gin, a social lubricant and painkiller to deal with rapid social upheavals. It can be hard to say entirely if that is good or bad to have an effective painkiller in tough times, whether music or sitcoms.
None-the-less, video can be a useful tool for education or cultural togetherness. People have made that point in some replies. A book by Henry Perkinson called "Getting Better: Television and Moral Progress" makes the case that TV helped broaden social norms in the USA to help move past prejudice and narrowness (like on race relations, an example being Lt. Uhura on Star Trek, the first depiction of a black female in a command role in US TV in the 1960s). There are some current TV sitcoms, documentaries, and news shows that sometime bring up important issues. I myself am, to a large extent, a creation of 1960s and 1970s TV -- PBS back then, the Thunderbirds, Star Trek, Space 1999, Sealab 2020, the Yogi Bear Show, the Andy Griffith Show, Gilligan's Island, Green Acres, Mr. Rogers' Neighborhood, and so on. They were not the only influences in my life (church, summer day camp, family, construction toys like TogL's, electronics from Radio Shack, neighborhood kids, school, etc. also mattered a lot), but TV stories were important moral shaping forces in the nature of good storytelling and in inspiring the imagination.
Humans, more than monkeys, are "Monkey See, Monkey Do" creatures, and a video of someone doing something can instruct in some technique or show a role model, like in Mr. Rogers' Neighborhood (even if according to the medical community, screen time is best avoided for kids under two, and limited after that). With the rapidly falling costs in video production, more neighbors can share videos with each other, like on YouTube. And they are. So, our society faces a big challenge now to integrate the idea of digital video into our lives in a healthy way. As above, it is not the only challenge though.
As for me, I have mixed feelings working in the broadcast TV industry (as I have had for most jobs I've done), even as I try to do my job to the best of my ability. As above, I benefited a lot from TV in my youth, but I also think it can be an unhealthy "supernormal stimuli" when overindulged in. One problem is that probably 90% of jobs in our society are either useless or harmful to some extent (see Bob Black on "The Abolition of Work"). Yet, our culture still collectively believes in this imaginary concept of fiat dollars used to ration access to food and shelter, which gives money some reality especially in the absence of a basic income. For a lot of the other 10% of jobs that are meaningful (museum curator? plumber? independent journalist? musical therapist? reading tutor?), people compete a lot, and/or they take years of apprenticing, and/or those jobs don't pay much and so to have one you need a spouse with a big income (working in the 90% of other jobs). I could work in the auto industry, and lament about socially isolation from personal cars. Or I could work for Google and lament the loss of privacy. Or I could work in medicine, and lament how most heart surgeries are needless compared to good nutrition (see Dr. Joel Fuhrman). I could work in the health insurance industry and lament how we would be better off with single-payer Medicare for All. I could work in the organic food industry and lament how the meaning of the term "organic" has been reduced and how people are eating organic sugar instead of organic vegetables or how I was mainly producing for the affluent. I could work on computer games and lament how kids were not getting enough physical exercise. I could work as a school teacher and lament taking part in what John Taylor Gatto calls the dumbing down of the USA. I could work in the defense industry and lament security theater and the irony in my sig of using technologies of abundance to potentially create global scarcity. I could make custom carpentry, and lament that it was mostly all going as a reward to the 1% who helped create a rich/poor divide by lobbying for regressive tax policy. And so on. Or I guess I could focus on positives in those various industries instead of, or in addition to, laments. Maybe I could do better as for meaningful work, but after decades of trying to make free and useful educational and communications software and open content (to little financial success), it is hard to go against the power of the marketplace and "The Pleasure Trap" and "Supernormal Stimuli" indefinitely. It has to be a collective effort to move forward, although every collective effort is also made of individual efforts. At least my wife can have some time to still work on free alternative stuff. And at least I can tell myself I don't work for Fox News. :-) Even if Fox News does indeed raise important issues too, now and then. :-)
As Theodore Sturgeon said in defense of sci-fi, when people kept pointing out all the schlock sci-fi stories, "Ninety percent of everything is crap". The same is true no-doubt for broadcast video. According to various industry pundits, broadcast TV's days may be numbered to probably a decade or two more as a major force in our society. On-demand (and often user-produced) internet video is the rising star, even if still small for total hours watched, as is obviously other internet social media (although that is often used while watching TV). What will shape that change, according to pundits, is where advertisers decide to spend their dollars, which are still mostly going to broadcast TV right now. Or, I might add, what will also shape that change is the degree to which we have a money-driven exchange economy dominant in our society (compared to a gift economy, subsistence economy and/or planned economy).
Perhaps the bottom line is that, to the best of our knowledge, we can't relive past time. So, we can't go back and redo the past fifty years knowing what we know now, assuming that would even make a positive difference given other factors we may not understand. We can only take what we have learned and figure out how to move forward from where we are now as individuals and as a society. Digital video can be a useful tool. How can we best make digital video part of a healthy society going forward? And how, in other ways, can we work to restore healthy communities with aspects of what you described as history? The Amish have one approach (tight regulation of technology, with every item scrutinized for its effect on community life, on the premise that just because you can do something, that does not mean you should). But even the survival of the Amish is based on aspects of the larger global culture around them (including refraining from nuclear and biological war) which they do not directly engage in to try to affect (except by setting an example). Are there other options to create, regenerate, or support healthy 21st century communities that embrace aspects of modern technology? Blue Zones is one place to look, for their work in Albert Lee, MN.