I wonder if the missing piece here is an agent layer.
A lot of decentralized/local-first social projects improve the protocol story, but the UX is still "please think about keys, storage, sync, exports, and trust boundaries yourself." That's fine for hackers, not for most users.
Something Claude Code-like, but local-first and protocol-aware, could make this much more approachable. The user says "post this to close friends" and the local agent handles signing, encryption, storage, syncing, and recovery.
That doesn't solve discovery, spam, or network effects, but it might solve a lot of the usability problem.