Remix, along with the other frameworks/libraries you've mentioned, are very interesting. I've considered trying out SSR with Quasar (the Vue framework I work most in), though selling it to "business" is hard and I understand why, I can't bring myself to eat the cost (both time and real dollar cost) on my own projects. I do hope SSR continues to advance, though I have some trouble imagining a "free"/"seamless" fallback for no-js users and so other than initial paint I'm not sure how functional some sites will be.
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).
Yeah as of now I think the SSR capabilities of NextJS and NuxtJS will serve mostly for the first paint, it will also allow a user to navigate between pages without running JavaScript (which a SPA wouldn't). I do have to agree though that at a certain point thinking further than this about non-js users becomes too cumbersome and not really worth it if your application is truly a web _app_ meaning very interactive and to the point it could be bundled as a desktop application.
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.
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).