Your second paragraph disproves your first. Websites' needs didn't drastically increase (I'm ignoring nonsense like WebGPU; render graphics outside the web browser like a God-fearing Christian!), but their complexity did. Why? Well, we told everyone with a pulse they could make six figures "doing web development", and we're reaping what we've sown.

You can still design websites like it's 2005, and they'll be damn fast. But pitch something like MFC or even PHP to a 20-something frontend developer now and watch the blood drain from their face.