I think you are missing the point. Development became accessible that’s why you see more of entry level discussions then deep one.
All the things you’ve listed are good things, but advanced. Only people that spend much time delivering real products are aware of them. That’s why you don’t see many people discussing them. The most part of web development community — new developers. They are not aware of the deep concepts, they just started to play around with tools. Tools are easy to discuss, they have defined bonds and names, and even a web page.
And don’t forget that you’ve grown too. It’s not the react ruined web development, it made web development more accessible for new members. And now the core conversation around web dev shifted to novice spectrum.
You grumpy old man and they are kids with skateboards))