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.
Posts and comments is one thing… It’s inherently public. But I think being able to see up and down vote publically is a tough pill. If you don’t realize your votes can be seen you risk your vote being held against you. If you do know it disincentivizes you to use the vote system to protect yourself from something that should be rather benign.