If you consider Reddit as a whole, with millions of users, I don't think there's any behavioral change you can institute that will lead to high quality, informed discourse. High quality discussions take hard work, not just in the discussion process, but in all the things that come before it. Also, the information gathered by hard work is often gated.

If you are looking for high-signal discussion, then most people in or out of Reddit don't have anything good to say on most subjects. Reddit is the wrong place to look for that kind of talk. Reddit is the right place to listen for community temperature about a narrow range of subjects which communities would be good for, such as user reviews or product discovery.

Groupthink is also not the main problem. How are you supposed to have your own individual opinion on a wide range of phenomena -- unless, of course, you make yourself informed via hard work and gated access? So these people cannot be expected to have their own opinion.

If you want elite opinion, then join an institution with institutional access to elite literature, and join an academic or professional community.

Reddit is fine as it is. It's not supposed to be an elite source of information on a variety of phenomena. It's a place for humor and community discussion. I actually dislike the segment of Reddit users asking for "citations" because unless you have institutional access, then I think that this call for citations is a dishonest way of shutting down conversations.