Earlier quoted context omitted.
Because in practice there is little value in making easier things easier. While 95% on the web are small projects, 95% of work is done on large projects. Many developers also dislike using many different frameworks, because that would require more learning. If you have to choose one technology it's better to use one where you can do everything. Not one where you can do 95% really fast, but 5% not at all. I personally…
The "big" projects can do what the hell they want. They can afford to throw a ton of money at a problem. The small projects are where the people I care about are struggling.
Then if that's not enough, you've got things like HTMX if you're keen on doing everything in terms of html templating, you've got tools like Svelte if you want an isolated chunk of dynamic UI in a mostly static page, you've got bundlers like Vite that just work without any configuration if you get to the point where you need a build step, and you've got a multitude of lightweight frameworks for the next step.
And on top of that, pretty much all the old ways still work. The browser is an incredibly stable environment! Outside of a handful of security-related removals, if it got into a mainstream browser, without a feature flag or an explicit "experimental" warning, it's pretty much there for life. So if you want to go back to the old ways, there's not much stopping you - but a whole bunch of quality-of-life development improvements along the way to make things even easier than they were back then.