You know the people that feel a need to tag their friends in a comment on funny posts? That's the kind of user that reddit hasn't been able to convert. Whether reddit wants or should try to garner that traffic/content is a choice they need to make, but the site is doing fine regardless.
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.
Isn't that...Reddit?