I don't care how my shoes are made. I buy them in the store, and I don't see the manufacturing process. I have a vague assumption that there's lots of automation in there.
On the other hand, I do notice how people interact with me, and in many cases this does make a difference. Let's look at depression therapy.
Your (2) is useful for light cases of depression, perhaps, but most people have such social groups already, and a seriously depressed person is not going to be in shape to construct such relations. I don't understand what you mean by (3). Your (4) appears to just give up on all the serious cases, and as a formerly serious case I don't really appreciate that.
It is possible to come back from clinical depression. In my case, it took drugs, talk therapy, and a lot of work on my part and support from my family and friends. All of those help, and are not necessarily sufficient. Talk therapy is going to be human-only for a long time. I read the books, and practiced the cognitive therapy (much of which I'd figured out on my own), but talking to an actual human with skills and training in this helped a lot.
BTW, I don't think I've ever gotten talk therapy from anybody with a Ph.D. It's normally a Master's in social work.