It’s illusory at best. You can create a note/event that functions as a “delete request” of a previous note. Some clients and relays will respect the request, and others will ignore it. In general, I think it’s “not great” because it may give users a false sense of security in believing their old notes are actually removed from the internet.
Edited notes - similar problem - but Amethyst handles this well, by showing the edited note and referencing the original version.
Hope this helps 🥂