The mistake is in thinking everyone _should_ care about everything and therefore everyone _must_ see everything. Outbox/Inbox ensures that you can see and interact with what is important to you, and ignore the rest. Smaller relays gives people the ability to have access to a wide range of npubs, but focus on their own cluster and store their own data, by creating a system of hops. I can move events from the Citrine relay on my phone to fiatjaf's personal relay, just by including an @ to his npub, in the note. It's like a mailing address. That's why we refer to the system as "mailboxes". I don't need to know what else is on his relay. I would just need to see his response, sent to my address.