I wonder if it is willful collusion among all the big social media sites that they are all simultaneously becoming terrible, or if they are just all reacting to similar stimuli in identical ways.

i work in tech and have a NDA so i can't really get into details but a lot of this is just capitalism doing what Marx said it would do. I would say it's less wifull collaboration than its people stealing each other's terrible ideas but I could be wrong since I'm not at the level where I'd be privy to those conversations.