Fundamentally, karma limits were mostly used as an anti-spam measure, if a rather crude one. I was actually a mod of a couple relatively large subs, and while I did feel bad for the impact on new users, the benefit from how much spam we caught with it made it ultimately worthwhile. There very well may be better approaches out there though, and I am excited to see how things grow here, but it is going to be a problem that the Fediverse will face as well.
I do wonder though what a better alternative might be (and if this has been studied at all). It’s fundamentally an issue with people being emotional and often quite bad at separating their own personal feeling from their voting. I know some platforms simply disable downvotes, which partially solves the issue, but at the same time, I think there is some value in communities being able to downvote spam or genuinely poor content. Maybe if you had to also make a comment - thus upping the amount of effort required - it’d be better?
Kbin does also have the quirk that votes are actually public, so you can actually tell if someone is following you around downvoting everything. That could potentially be seen as a rule violation and lead to being banned from an instance.
Literally just learned that it exists today from this post.
That’s an interesting idea, though I’m wary of the risk of funneling users into echo chambers. Just think of YouTube around 2016 when every gaming video led you down a rabbit hole of Gamergate to Ben Shapiro and ultimately raw white supremacy.