Your votes on Reddit are public to Reddit admins. On Lemmy anyone can be an admin.
Which is my concern. I don't like Reddit having and selling that data, but it's easier for me to trust-ish a singular entity than some entire web of random people, which probably includes some corporate people siphoning data anyway. I know some would likely find that a tad paradoxical, but that's how my brain works. At least then the corporation can be held accountable per the standards of the region they're based in should there be issues, or users can mass target the corporation rather than go "Don't like it, just move to another instance.".
For reference, it's still not ideal, but I'd somewhat trust my instance's admin. Why can't my vote history be shared purely with them? Then give other admins the raw upvote/downvote data of the post/comment. After all, the instance I choose my account to be on is my decision.
Your Lemmy name shouldn’t be tied to your real name.
It's not. I am careful about what I put online. Whilst I'm uncertain as I've never particularly tried to do so beyond some cursory Googling, I'm pretty sure you can't tie my username back to me IRL. But even so, there's no need to add to the pile of potentially traceable publically available data.
The purpose behind having votes be more public is to have some kind of reputation behind those votes.
That can still be anonymised behind a hashed ID. If all my votes were registed to some User-XXXX and it wasn't possible to retrieve my username from that, I'd have no issues. Though from my discussion with other people, it seems that's counter to how ActivityPub intrinsically works. I'm increasingly working towards the opinion that the fediverse isn't for me, if it's all set up in a similar fashion and apparently unchangeable. As they say, "different strokes for different folks" I guess.