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.
Also. Whilst reddit mods might not get access to that information. It is definitely stored somewhere. On reddit, you can see all your upvoted and downvoted comments and posts. And lets face it. I highly doubt reddit are encrypting that information and hiding decryption keys away from every reddit employee.
I really don’t see the issue here.