It can easily be a huge waste of time while still feeling like it's enriching. And even if it is enriching, if it gets in the way of other stuff you really need to to be doing, then it's a problem.

Hit the nail on the head. I've quit every other social media site with the exception of HackerNews. And while some would argue HN isn't social media, I would disagree; I'd argue most of what makes HN so popular is the commenters.

I've found that in this regard, HN is no less addictive to me than a site like Reddit. I impulsively check it when I'm bored and find myself wasting time in long comment threads that over the years I have found more and more pessimistic. Still far better than Reddit, but the pessimism gets to me to a point where I can't help but feel jaded. Anyway, I just don't think it's good for me anymore.