I made the mistake of discussing potential relationship issues using FB messenger, over the course of a couple of weeks my feed became almost entirely toxic memetic content; infidelity memes, cuckoldry memes, 'man up bro' type of content, incel content and a lot of gradual 'pushing out'; videos of men in the woods alone hunting, people living 'happily' in vans with dogs, alone, always alone, and with a vague hint of 'you can get your revenge' thrown in there - no specific 'calls to action' but a general destabilising push. Some of it was really really awful and bleak; the man alone in the woods hunting realising the only person he can trust ever is his ever-faithful dog, it was really toxic. Also 'homeless' - I think one day I must have seen the word 'homeless' in literally every single comment I opened. I've never seen a word so many times in my life. It was incredibly strange.
I could see a person who was already quite unhappy and isolated being driven to do something really stupid if they didn't protect themselves by pulling the plug, which I did.
In addition just about every single comment section everywhere has people stirring up drama. Reddit has had to ban 'crime' posts from local city subreddits because people flood the subs with endless 'CRIME EPIDEMIC STAY INSIDE IT'S SAFE INSIDE' type posts that serve only to create tons of anxiety. It's not accidental, it's something that's being done.
I do think that a lot of the issues with homelessness, migratory behaviour and isolation within society are caused by these platforms pushing this sort of 'ah just give up on society, be an island' mentality on people.
I'd say that it's now very very hard to maintain a normal state of mental health if you make extensive use of these platforms; very hard but doable if you confine yourself to a desktop, almost impossible if you have the apps on your phone.