You know, if I've noticed anything in the past couple years, it's that even if you self-host your own site, it's still going to get hoovered up and used/exploited by things like AI training bots. I think between everyone's code getting trained on, even if it's AGPLv3 or something similarly restrictive, and generally everything public on the internet getting "trained" and "transformed" to basically launder it via "AI", I can absolutely see why someone rational would want to share a whole lot less, anywhere, in an open fashion, regardless of where it's hosted.
I'd honestly rather see and think more about how to segment communities locally, and go back to the "fragmented" way things once were. It's easier to want to share with other real people than inadvertently working for free to enrich companies.
So it's not about owning vs. renting property on the internet, it's about controlling the roads that connect the properties so you can keep the world out of your community.
bad_social_network was good 10 years ago, because it was controlled by "a friend of ours". Now it's controlled by someone who's perceived as "a friend of theirs" and it's therefore bad. So the politik aktivists move to good_social_network, and rave about the good there. Echo chambers be damned, we have control. Until the next "friend of theirs" buys it out, and rinse and repeat. So silly.
The other never has.
There can be technical differences between networks as well as social.