Isn’t it called BitTorrent?

Yeah but then you run into the risk of federation/defederation politics. We’ve already have had a major instance defederate.

I disagree. The large Mastodon instances have managed to survive for a while on donations. I haven’t seen a large Mastodon instance go kaput (though you can correct me if I’m wrong).

I would add that the risk of joining a small server is that the owner can suddenly delete them at any time and you would have to start all over again elsewhere. Best thing to do is to make an account on the large instances only.