Social media websites are the only way most people on the internet have to express themselves. Which is really sad if you think about it, most people's only presence on the internet, is uploading data to other people's servers where they no longer have any control in it.
There are a bunch of people, like me, who upload stuff to our own servers (very occasionally). It is marginally more expensive than social media (my server is a raspberry pi) but it enables me to say whatever I want, whenever I want to, to whoever I want. No one else owns the server where my posts live, so they can't stop me posting there.
My gemlog posts are not that different to someone else's Twitter or Facebook posts, but I have 100 times as much freedom. We don't need social media sites, because the whole internet is social media. As a side note, I mean the whole internet, not just the web.
If you are currently using much social media, consider whether you need it or not, since the internet itself already does everything we need, without being owned by a corporation.
In conclusion, the internet is the best social media.