Let's assume social networking is worthless per your judgment: Do you honestly think this problem will go away if centralized social networks go away?
Unless you want to make it illegal for individuals to widely share content without going through an editor, this kind of problem isn't going away any time soon.
https://www.forbes.com/sites/kashmirhill/2014/06/16/supreme-...
On June 1, 2015, the Supreme Court reversed Elonis's conviction in an 8-1 decision. https://en.m.wikipedia.org/wiki/Elonis_v._United_States#Deci...