Discord is a bunch of chat rooms - fundamentally not a forum or fora.

Reddit and Lemmy are message boards full of fora, with each forum inside them full of threads which have branching threads inside them, and so on. Their distinguishing factors are really their methods for sorting posts and discussion threads, but those methods are really significant. Old fora had no voting mechanic.

Whether or not life is superior with a voting mechanic is a subjective question, but I absolutely loathe how on Reddit any post that either dissents from the hive mind or is perceived to gets downvoted to oblivion and suffers additional consequences, like how no-one will answer honest questions if the hive has decided that they don't like it. Personal example: I once asked on the linguistics subreddit why descriptivist linguistics were preferred to prescriptivist and was downvoted to hell and back. The only replies were to call me a racist. I never got an answer, and I still don't know. So voting is not the end-all be-all of forum mechanics.