Reddit's system has its issues too. Early comments always get more votes and have more sway than later ones, and the "reality bubble" effect is worse because the general consenses upvotes posts that agree with their opinion and downvotes ones that disagree - effectively hiding them whether they're factually correct or not.
Hacker News is much better than Reddit in general for allowing comments on both sides of an issue to be heard, but it's not perfect either. I think it benefits from not being able to see the number of votes on someone's post because it removes that way of checking the previous hive consensus. I'm not sure I even like the greying effect on heavy downvotes.
The best real discussion (especially for ongoing topics and events) I've seen is still on old-school forums like SomethingAwful. The barriers to entry help ($10 on SomethingAwful, 500 points to downvote on Hacker News) but I think Discourse went too far in that direction, where anti-spam limits can make it hard for new users to even write a good post or respond when they want to. I'd like to see a modern forum site where anyone can create a subforum and moderate it themselves the way anyone can create a subreddit on Reddit.