I think this is a good analogy, though something I've noticed is that as reddit has taken their product direction more towards social media, it seems that it has been harder to maintain quality in smaller discussion subreddits, because popular posts get picked up and injected into non-subscribers' feeds, so the ability to have a subreddit approaching HN's level of conversation is reduced.

Increasingly it seems users have no concept of subreddits at all, and simply consume a singular home feed (I don't actually know what the new user experience of signing up for reddit on the app looks like, but this is my impression), more like the major social media platforms.

I've been using reddit for a long time and still check it, but I've become considerably less engaged as they've moved towards this kind of lowest-common-denominator slop trough feed approach.