I also really enjoy knowing I literally own all my own data. It’s stored locally on my personal server.

As far as I understand the fediverse, that’s not necessarily the case. Let’s take a local community with a post or comment of yours as an example, and see how it could go wrong.

When users from other instances subscribe, the community is copied to their instance, including your content. If federation is broken, or any of the two instances go offline, you can still change or delete your local data, but not the remote copy.