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.
Until you get rouge instances or rogue admins on seemingly reliable instances willing to fuck with vote numbers for money. A full open system does help with accountability and the ability to discover corruption/deception by admins. I’d rather have the openness than allow instances to create their own fiefdoms with no externalized accountability in an open federated system like this.
The scummier versions of old reddit power mods are probably salivating at having their own instance farms to sell upvote services to advertisers and nefarious groups to with the concept of hiding vote details from downstream instances, so it is easier to obfuscate their activities and more difficult for external analysis to discover and expose.
Keep it all open and just advocate and educate the end users to create anonymized user accounts with unique emails if they want their personal privacy.