I think we should stop seeing Lemmy as just a substitute for Reddit. Lemmy can be it's own thing, without having to do 'reddit-like' stuff.
Imo, I don't think the karma system is really necessary (it doesn't even make sense) and the upvote-downvote is good enough to filter quality posts.
In my country if you live in less populated areas, you could easily drink tap water. But in bigger cities, it's not 100% safe so you have to install a water filter.