@arcanicanis @i @mint @foxxy To add to that, at least one instance software explicitly has a feature where you can reject deletes, and many of them either openly or subtly use this on the entire network.
https://docs-develop.pleroma.social/backend/configuration/mrf/

And then on top of that, many fedi instance stacks do not "clear" old cached media, so a deleted post can sometimes be seen with the old media intact on one of these instances.

That's not getting into stuff like boardreader scraping one fedi instance a while back and that same instance owner getting clueless FBI agent emails about content hosted on other instances (some instance user made a post that got the user banned on another instance threatening a certain rich American oligarch who runs a company that rhymes with Crack Rock).