Remix provides something close to what you are thinking, the application works perfectly without JavaScript but gets enhanced if it's enabled which is pretty nice.
edit: Without code duplication of course
edit: Without code duplication of course
I specifically called out "web apps" in my first comment as I do understand the value SSR brings to things like blogs, news, or other simple sites where JS is not needed, or where it can have a clean fallback. On the other hand, I write "apps" (sometimes deployed on phones via Quasar/Capacitor as well as on the web) and those get much more complicated. I'm not quite sure how modals, WYSIWYG, rich date pickers, etc translate for a no-js user. Simple navigation is easy enough to grasp but my understanding is that things like NextJS/NuxtJS are really just for first render/paint and then React/Vue take it from there. I could be behind the times on what's possible without JS and using SSR through. I just know the PHP codebase I also work in uses plenty of JS to be functional (not above and beyond, literally "table stakes" stuff).
I'd like to note that Remix does handle everything being tied to a single logic as far as my testing went, I love it. The idea is that basically all interaction is done with html forms (like in the old days) and Remix loads a React bundle that makes that run client side after the page has loaded. It's a very simple model that should work for most use cases, although I don't think it's suitable if you're truly developing a web _app_.
As with everything, balance is key. JavaScript is useful and more appropriate is some situations, and it's not in others. I do hope to see more progress with seamless SSR for SPAs though, I think it would make the internet a much better place.