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.
I would expect they’d collate that information and pass it on at regular intervals to the instance that holds the true version of the post, who then subsequently disseminates that information to subscriber instances.
Then again, I guess you could collate the detailed information in a similar manner.
Not disputing what you’re saying, I assume you’ve tested this out and that’s what you’re reporting, just commenting on the choices made by the project to implement it this way.