Edit: obligatory explanation (thanks mods for squaring me away)…
What you see via the UI isn’t “all that exists”. Unlike Reddit, where everything is a black box, there are a lot more eyeballs who can see “under the hood”. Any instance admin, proper or rogue, gets a ton of information that users won’t normally see. The attached example demonstrates that while users will only see upvote/downvote tallies, admins can see who actually performed those actions.
Edit: To clarify, not just YOUR instance admin gets this info. This is ANY instance admin across the Fediverse.
That won’t help AFAIK. For example, your comment seems posted on lemmy.world, in a lemmy.world community, yet I can see it on Kbin. If you delete all your data on lemmy.world I can still see it on other instances, since every instance has received a copy.
As usual on the internet, treat everything you post as public and irrevocable.