Only the outbox lists must be everywhere.
The outbox list is like a DNS, it points to where (which relays) your metadata, mutelists, follows ect are. So, you don't need these other events everywhere. They can all be hosted by the user's home relay.
Discussion
well, that makes it simpler
relays could be broadcasting updates to them and fix that problem, still need some sort of rate limiter but this narrows down what you actually need to give auth-free access to