https://en.m.wikipedia.org/wiki/Eternal_SeptemberEternal_SeptemberEternal_SeptemberEternal_SeptemberEternal_SeptemberEternal_SeptemberEternal_SeptemberEternal_September
I think HN is both an amazing place to find content and also to meet the top experts on a variety of subjects (very often articles about a technology or research field will have the creator or most influent researcher in the comments answering questions and listening to feedback)
If you'd like a more curated feed, you can use: https://news.ycombinator.com/best
Subjectively, yeah, I think the quality of the discourse here has gone down, and I would say I feel like something of an "Eternal September" effect has had an influence. But I can't really prove that.
That said, while I get annoyed by some of the stuff I see here lately, this site is still more fulfilling that most similar sites, so I still spend more time here. I have been gravitating back to Slashdot a little more lately though, just for a different take on things.
Next? Well, there's an invite only site called lobste.rs that is largely populated by ex-HN'ers. They keep it invite only to try and avoid that watering down / culture change effect. The flipside is that the amount of traffic there is much lower.