Addictive, sure, but stupid. Ultimately that leads for smart people to leave, making the content dumber by the day. You can argue that the same thing happened to Usenet during eternal September, and you would be correct.
HN is so valuable because it’s curated by its users, and so far, they prefer intelligent content, but just imagine what would happen if HN had its own eternal September and all of reddit decided to visit. I mean, /r/technology wasnt always the political battleground it is now, and /r/programming wasn’t always teenagers arguing about what language will replace what.
When you allow everyone to speak on equal terms, all you get is squabbled noise, and it’s often dominated by the people with the most free time, and those typically are the people with the least to contribute.
Of course the internet hasn’t had a great deal of luck with curated forums either. Especially not if it didn’t want them to be echo chambers. But I suspect the first technology or media house, or perhaps library, that manages to make a curated forum for intelligent content and debate will have a lot of followers. Because all those platforms we no longer use, like Usenet, were actually really good, until they were ruined by the noise.