It'd be a lot harder to run them, that's for sure. This is not an easy problem. There are obviously a lot of upsides to social media: stack overflow is very useful, I think hacker news is a positive contribution to society, and even FB and youtube and such provide a lot of positive value.

That doesn't mean that they aren't also capable of producing enormous negative contributions as well. As useful as stack overflow is, how does the magnitude of that positive contribution compare to e.g. a Myanmar genocide?