Like any long-standing community, certain aspects of the "flavor" of the community have changed over time, as members have come and gone. @pg and the other HN staff have tried to fight the "eternal september" effect, but you can question how successful they've been. Anyway, more than a few of the members here who have been very popular and valuable contributors have left for one reason or another (and, I'm sure, plenty of less "visible" folks as well).
One community that gathered at least some of the former HN crowd to attempt to maintain a specific culture, is Lobste.rs. It's a smaller community (partly by choice, as you have to be invited to join) so there's less overall traffic and discussion to be had, but it may be that the discussion that is there, is of a level closer to what you're looking for.
https://lobste.rs