> Only some interventions showed modest improvements. None were able to fully disrupt the fundamental mechanisms producing the dysfunctional effects.

I think this is expected. Think back to newsgroups, email lists, web forums. They were pretty much all chronological or maybe had a simple scoring or upvoting mechanism. You still had outrage, flamewars, and the guy who always had to have the last word. Social media engagement algorithms probably do amplify that but the dysfunction was always part of it.

The only thing I've seen that works to reduce this is active moderation.