i said this in a comment a while ago but i think it deserves its own journal because it was kind of getting off topic lol. most of this is unstructured rambly thoughts so feel free to not read any of this

i've been doing a lot of thinking about the future of social media and what's likely in the next decade or two, barring some capital D Disaster happening that makes any kind of internet fundamentally impossible. with the current state of megaforum style social medias like facebook, twitter, reddit, etc, i've noticed that the goal of shoving every kind of user in the same space kind of sucks, and leads to phenomena that makes everyones social life worse on the internet and outside of it. see: "main character of the day", "lolcows", "cancel/callout culture", troll/bot farms, outrage marketing, etc
which like, i think the prevalence of this stuff would not be so Widespread and such an Issue if people weren't forced to all be on the Same Place. a place where a ton of artists go isn't going to interest a guy who wants to talk about sports. a place where christians go isn't going to interest die hard atheists. but making a Platform with a Generalized Audience means that people are going to argue incessantly and that platform will eventually be viewed as a toxic cesspool solely for people who like to argue. and people who understand social engineering and how to sway opinion based on negativity are going to flock to those platforms and stir the pot even more for their own gain.
and of course, the people running the platforms themselves stand to gain from all of it, and will happily take ad money for the place people are addicted to arguing on, and will only step in to protect themselves from liability. sometimes these people will encourage outrage for the same of keeping people glued to their screens, regardless of the social ills it causes- see how facebook and youtube get shit all the time for their algorithms pushing hate speech. they get money for it. they benefit from all the manosphere/incel/maga/etc shit (and it helps that these types happen to have very deep pockets and love to spend on ads for their bullshit- the reason that facebook went so hard right in the first place was due to a certain american president's campaign being their biggest customer.)
i don't think that social media like this will last forever. sure, it might stick around in the same way that shopping malls in the US do, in their dying and decaying form, but if you've been in one in the past decade you've probably noticed how many of them rent out to the businesses that used to run those scammy kiosks. the companies that own these platforms will drive customers away with their shady practices, squeeze rent money out of their anchors, and end up having to scrape the bottom of the barrel for profit until either the platform is condemned for lack of maintenance or goes out of business entirely.
unfortunately for us users, maintaining platforms requires money, so it's kind of hard to self-host in the long term. but the thing is when the intended userbase is smaller, you don't have to convince everyone on earth to join the eventual replacement. just your community