you can but many relays don't honor the delete messages

i'm sure the situation will eventually change

i think that expiring messages should be a thing too, it's an easy cache management strategy, most databases put stamps on versions and clear out the ones that are old or beyond the history recording limit, on telegram and other chat systems there is the notion of expiring messages

yes, i know, i know, you send the message out, it's gone, but it's just good manners to grant such a request

ultimately there will be archivists who treat every event as immutable and eternal but they will usually charge for access, which i think is how it should be