The idea that you "can't delete stuff on Nostr" is a misdirection about what Nostr actually is. Nostr relays are just independent web servers. You absolutely can reach out to a relay operator and ask them to delete your stuff from their relay, as you can with any other website. In some jurisdictions they are legally obligated to do this. Kind 5 deletion events just automate this process. When people say "you can't delete stuff on Nostr" they mean you can't easily automate the process because of the same problem Outbox Model aims to solve, and/or that there are jurisdictions where relay operators don't have to care or choose to ignore you anyway. However this is not actually different or special from anywhere else on the internet, except that maybe on Nostr your content can travel to more places faster to begin with. It's not really an excuse not to try. When you delete stuff on the Fediverse, it gets removed from 99% of places automatically because the developers have decided to try instead of resigning themselves because "it's too hard" or will "never be perfect anyway".