What's a general news forum with high quality commentators you think is relatively devoid of astroturfing?
Honestly, I think it doesn’t exist.
But Reddit in particular is nasty about this. I think HN does a bit of a better job but the issue here is that the majority of users are generally well off. This skews the discussions.
Ghislaine Maxwell, for instance, was a mod on /r/worldnews and one of the most prolific posters.