If I think about my own use of social media (and I have a facebook account from waaay back in the day, shortly after they dropped the requirement for a US edu email address), I wonder what value it ever had, over and above just emailing those people I'd like to stay in touch with every-so-often (which is what I do now). The reason why facebook switched to an algorithmic feed is because the previous method was failing, people were starting to give up posting. Algorithmic feeds didn't kill social media, they were an attempt at keeping alive what was already moribund. Social media, in the strict sense (so, not just online clubs or societies), never needed to be invented.