For me its having a single instance that indexes all the communites to which all other instances can then pull that information from so when I go searching for communities the I’ll have access to every single one with needing to post the entire URL in the search bar
Software engineer here. Historically we started not hard-deleting anything because sometimes software does bad things and we never want to accidentally delete anything that could be important since then the only way to undo it is to restore the database from a backup. So it’s better/safer to literally not allow the application to ever delete anything from the database.
That being said, I could see an option in ActivityPub to delete comments, but with the distributed nature of Lemmy you would have to trust every server you federate with to listed to the protocol and delete the comments too since they are stored on the other servers as well.
I fully understand wanting to restore things from a backup, but I don’t grasp how giving us the option to hard delete our own posts and comments would interfere with that in any way. Safest? Perhaps. A reasonable tradeoff for such safety? Not in my opinion.
As for your latter point, maybe that’s one of the drawbacks to federation that does not get discussed enough. However, I’d think there’d be some sort of solution to put more control of our data into the hands of the users.