I understand the need to recreate a familiar experience in e.g. deleting a tweet on twitter.

I don’t understand how it’s possible to ensure all the relays delete a certain note.

Maybe my non-technical understanding is off: all you need is one relay to not cooperate, one bot to take a snapshot of a note the instant it is received on a relay.

This note now exists, and deletion requests will not be honored.

It is not fair to a new nostr client user to state/have a “delete” button, when the note is stored somewhere.