Where posts are full of embarrassing ideas or typos,  deleting is a sledgehammer to crack a nut. Surely an easy solution is, replying to yourself and putting in a disclaimer or explaining yourself better. That subscribes to the idea of owning mistakes and showing growth.

But where an error is disastrous, accidentally posting a private key, that needs some sort of consensus from relays to delete or within apps, some way of parsing and flagging before a final publish. Like where say URLs aren't recognised on some forums etc