because the whole point of post-office protocols is asynchronous delivery

you can only obfuscate the message, you can't hide the existence of a message. being that almost all nostr events are plaintext content they stand out like a sore thumb even without kind giving it away.

the reason why nostr uses a POP is because it's impossible to arrange that everyone be online at the same time to relay the messages, so you need to have specialist nodes in the network for this. and you have to ultimately trust them, which means that the relays MUST protect privileged messages like DMs from being fetched by randos. which means you MUST have auth.

imagine email without auth. ridiculous. yet so many supposed smart guys in nostr dev don't get it.