i solved this issue (even before nostr existed) when i wrote #treebit In treebit (also a twitter-like clone) peers connects to peers and all communication is encrypted. no central servers at all. basically exactly the same as bitcoin in that way, but no global state. the price to pay (aka no free lunch) is that data propagation is slower (needless to say ”bridge nodes” would solve this, because those would be similar to nostr relays).