Deleting a post is simply marking a piece of text so nobody sees it, but I think the text is still stored in their servers.
Furthermore, a large company like reddit, must backup regularly, meaning there must be several copies of my posts in several SSDs. If the backup once a day… some of my posts are 5 years old.
Companies exist to make money. I suspect they just marked my posts not to be readable by anyone, except staff and they can still monetize them.
Am I wearing a tinfoil hat way too often?
Yes, the important point here is editing all posts, let them sit a day so they are snapshot and then delete. They will typically only restore from the last snapshot.
Of my 2000+ deleted comments only a handful were restored by them. I just re-edited them with more spez scorn.