I don't even know that karma/upvotes are good for ordering threads or comments. It just encourages gamification, group think, and snark.
I'd say get rid of down votes, replace upvotes with emoji reacts, and sort based on reacts + replies, but that's probably just encouraging gamification, group think, and snark, too.
Reddit, like other centralized social networks that are trying to monetize us, prioritizes time on site and generic "engagement". Those are what generate the most money for the company.
They're not what's best for us as users.
Maybe what we need to do is allow users to quickly and easily hide comment chains - not just collapse them, but dismiss them entirely - and allow for user-scriptable and shareable sorting algorithms. We drop down votes entirely, because they're just used passive-aggressively anyway, make blocking users as easy as possible, with temp blocks and notification silences at the ready, and then forget about user reputation points entirely, because they're as meaningless as Dragonball Z power levels.