Parental responsibility is a huge part of the issues relating to social media, but there are key distinctions between it and the "TV pollutes your minds"/"chewing-gum for the eyeballs" arguments of yesteryear.
The first obvious one is that TV shows weren't strictly engineered to become addictive through the weaponised use of the dopamine reward cycle. The second one would be that the parental generation(s) we're talking about here are by and large, trapped in the very same addiction - and so like many folks with dependency issues, rather than admitting to a problem, they attempt normalisation it in the most literal way they know how - by introducing it (i.e. push it upon) everyone around them including their kids. (Things are perceived to be less harmful if *everyone* is doing it right?). I don't think the same sort of thing was going on with MTV to be honest.
Also, subjectively "harmful" content historically wasn't completing for the same base commodity (i.e. individual attention) across such a wide demographic - social media companies differ massively in that the intersection between the content turning their parents and kids into the same somnambulant constrained thinking machines is essentially the same. Parents weren't sitting down with their kids to watch B & B together as a group activity; you only need to sit in any modern restaurant to see that whole families are all locked into the same consumption cycle when it comes to crap like Insta, TikTok, Facebook and the like.