HTML was never gone :) I have and still working on big e-commerce websites.
For example, Ikea for product lists sends mini chunks of simple HTML. No JS involved.
What I see is the problem that people think that "Frontend development is easier than backend development".
For me, they have different challenges and different ways of thinking. Getting a good full stack developer is kind of getting a good doctor, which has at least to specialities.
This always amuses me when it comes from junior front-end devs who are scared to touch the backend because they've never done it before. I always tell them not to worry: the backend is much simpler.
I hate that statement so much. Even had some serious arguments with "back-end developers" who were constantly mocking HTML/CSS/JS. Turned out that when pushed to do it, they just couldn't do anything and had to ask for help.
Writing proper reusable HTML/JS isn't easy, it also requires thinking on how to structure and split up things. Especially when you throw some CSS into it.
I can assure you those developers mocking frontend devs can't even do backend if taken outside their big ass framework (django, rails, symfony,etc etc), because they believe everyhing is as easy as those frameworks put it to them. Somebody that had to work outside of that where you have to take many decisions and make tons of trade offs and find how to organize code and manage dependencies, etc will understand better how difficult frontend is. True we sometimes overcomplicate things more than needed (redux, rxjs, etc...) but even when we do not, this is still freakin difficult to get right.
Can you elaborate how? like some turbolinks thing?
What you can see in the Network tab is that you get chunks of html from the backend which have all the markup
Other e-commerce stores do that too.
Sometimes these chunks also have js in them.