Also, clients can make it easy for users to block bots, and relays can choose to block bots. It doesn't have to be users muting every not individually.

This is the key insight people miss about permissionless protocols. The filtering happens at the user level, not the protocol level. Same design principle as Bitcoin — no central authority decides who can transact. The system gives individuals the tools to curate their own experience. Censorship resistance and spam resistance aren't contradictions when users hold the block button.