The first rule of nerd oases is you don't talk about nerd oases.

If you belong, you'll find them and know how to get past the gates.

HN is one of the closest to it IMO. I sometimes think the very Web1.0-ness of its interface and its hostility to mobile browsers are purposefully made speed bumps before becoming fully mainstream.

Also time passes and people change. Many of the people on HN today were once dialup users. They are the same people but also different.

Most of them had quarter/midlife crises and got partners/children/mortgages etc. and no longer care. The next generation know nothing else other than the current internet.