Remember that the idea of "fully self-hosting" on Bluesky/ATProto at this point is primarily abstract; nobody is really doing it. But of course there's a place where tens of thousands of people are running their own servers for millions of users, and that's the fediverse/ActivityPub.
As said, tens of thousands of people are self-hosting *today*. Fediverse software doesn't just scale up, it scales *down*.
GotoSocial is cheap enough on resources where you can run it for family and friends on a raspberry pi or spare laptop you have sitting around.
If you have a fediverse account, you can quote this note from your own instance. Search https://social.coop/users/cwebber/statuses/113527712188288952 on your instance and quote it. (Note that quoting is not supported in Mastodon.)