I call BS on that. The accessibility tools that people actually use only work with "proper" browsers (counting in IE here) that all support Javascript. Modern browsers don't even officially support disabling Javascript. For most web apps, the only feasible way to degrade from "no Javascript" is to display "this page requires Javascript". Spending any more effort here because it's "good practice" is a complete waste of time. Put some effort into testing screen readers instead.
> HTML is the web.
Nonsense.
> All this pure es6/dom stuff is a cancer.
Hey, who are you to tell people what to use the web for? If somebody wants to serve as static HTML page, nobody is stopping them. Nobody is forcing people to use some Javascript framework for that.