Build a protocol specification instead, and we can have multiple competing implementations (like Email). This is what Jack Dorsey was suggesting.

Based on cryptographic signatures.

If you signed your message with "This is a reply to msg 33419574 by dustedcodes. Signed: mejutoco", then nobody could take this converstion away from you. It would be federated by all competing services that use this protocal.

Sounds a bit like the Nostr protocol.

https://github.com/nostr-protocol/nostr