Earlier quoted context omitted.
No, most websites are still websites, and one of the biggest problem on the web is the plague of people who think their website should be an application instead. Actual web applications, like e.g. office suites, map applications, ect. are obviously extempt from "should work fine without JS" rule.
Are you really trying to say there's no argument to be made that SPA + prerendering is a design pattern with advantages over flat html, even for static content? Obviously there are disadvantages as well, but it's a tradeoff, and if executed correctly it's one that, as fewer people turn off JS and browsers become better at running web apps, is increasingly becoming worth the complexity for certain use cases.
Reimplementing these features in JS is often pretty feasible, and occasionally there are use cases for it, but it's a lot of additional overhead and it's not at all unusual to introduce bugs that really hurt the UX. (UX is not just adding as much branding as possible on top of vanilla browser behavior.)
The average newspaper website should not load 15 megs of junk from 20 different domains with a massive amount of Angular code just so I can read a single paragraph of plain text. This is an example of a document, it's what the web was made for and browsers already do it well without turning most documents into an SPA.