And I think your other point about removing downvotes leading to increased trolling would need to be investigated with better controls. You even said that the forums you’re talking about are “lesser-moderated”, so my mind immediately latches onto that as the reason for more trolls, while you see the differences in voting as the problem. I think moderation is the vehicle to decrease visibility, while votes are the vehicle to increase visibility.

Well, yes - that's part of it. Blahaj and Beehaw (two examples to my mind) are notably stricter environments than most other instances networked up. Currently, most fediverse instances don't operate to their level - and I'm not sure that it'd be welcome for them to do so. The downvotes currently, because of them being public - function pretty much as Reddit originally intended - used as a tool to hide malicious/trolling/bad-faith content or even simply off-topic posts (that don't justify instance intervention) rather than just haterating.

It could also be related to something like the number of users and traffic. Likely trolling is encouraged by many of these factors combined.

Well I can assure you as a local instance staff that there's a lot of annoying trolling, spam and AI splatter right now that is mostly bought to my attention by downvotes.

I would like a better reaction-system than just up and downvotes though, but it would require Lemmy not being the major instance software.