Without saying whether I think that's a good or bad thing, as a practical matter, I 100% agree. Approximately no major websites spend any effort whatsoever supporting non-JS browsers today. They probably put that in the class of text only browsers, or people who override all CSS: "sure, visitors can do that, but if they've altered their browser's behavior then what happens afterward is on them."

And frankly, from an economic POV, I can't blame them. Imagine a company who write a React-based website. (And again, I'm not weighing in on the goodness or badness of that.) Depending on how they implemented it, supporting a non-JS version may literally require a second, parallel version of the site. And for what, to cater to 1-2% of users? "Hey boss, can we triple our budget to serve two versions of the site, kept in lockstep and feature identical so that visitors don't scream at us, to pick up an extra 1% or 2% of users, who by definition are very finicky?" Yeah, that's not happening.

I've launched dozens of websites over the years, all of them using SSR (or HTML templates as we called them back in the day). I've personally never written a JavaScript-native website. I'm not saying the above because I built a career on writing JS or something. And despite that, I completely understand why devs might refuse to support non-JS browsers. It's a lot of extra work, it means they can't use the "modern" (React launched in 2013) tools they're use to, and all without any compelling financial benefit.