It's an interesting idea for sure, but I'm not sure how or if such a thing can exist. Moderation becomes a headache, and well, a lot of truly brilliant people I've met in life have zero interest in debating it. How do you keep out the YT commenters, Fox News or r/politics commenters, etc?
It would be interesting if HN had some bucket like /offtopic, for things that are flamebaity and removed from the main view, but I fear it would attract the aforementioned people who only ever troll there, and dang probably having zero interest in mod'ing it.
formalized highschool and college debate is pretty much this