did you guys ever check out ScuttleButt (https://scuttlebutt.nz/) It seems to have fallen off the rails, but it was a pretty brilliant Idea of encrypted peer-to-peer social media and messaging. Kind of like a complete mastodon instance running on your local machine and you have a list of "servers" that are really just other machines that you sync up with when you log in. So, when you turn on your PC, it has a list of your friends who are "on" and have registered their IP with anyone who has a "polling" station, kind of like a bittorrent tracker. Then it requests any messages in their out-box, directly. When they "made friends", they generated a key between them. So messages don't leave your PC until they're already encrypted, and then aren't sent until your correspondent requests them, and they decrypt them on their own pc using that shared key.
Unfortunately, it was a bit clunky and slow. But.... I love the idea of eliminating centralized systems entirely, especially now.