Reddit is frustrating, there is useful stuff on there (most of it from years ago archived), but it has some of the worst moderation I have ever seen, can tell many mods are power hungry. The downvoting thing needed to be gone like years ago but is still there, so it just creates massive hive's as you said, aka echo chambers.
I got my first and only perma ban about 4 months ago, no previous warnings or anything, and also for nothing in the rules, I had apparently upset a member, and that was enough to be gone, sort of thing, I later read that these perma bans which are not vetted by reddit staff can lead to an reddit wide ban under specific circumstances, most of these problems is because reddit is designed to be community moderated.
I also rarely make new posts on reddit, and stick to comment on existing ones, as I have a very high % of posts that get deleted for usually very vague reasons that are not consistently applied on the sub.
So yeah a gigabyte/evga or nvidia/AMD community on reddit would never duplicate an existing official forum. The amount of censorship alone kills the idea.