I'm not disagreeing with you but think we're already mostly there and wasm is the next step.
They take data in & transform it into structured hypermedia (html). Because the output is html not structure, users have the agency to run scripts & extensions, doing things like form auto saving or dark mode or modifying the behaviors of sites generally.
Part of what's so elegant amazing & compelling about Custom Elements & Web Components is that it helps improve the situation, gets us closer to good with our users. We have lots of promising things we can do to expose the computing on the page, but many popular framework's have steamrolled over a lot of these possibilities to pursue esoteric non-webful industrial fast paths.
I'd love it so much if, for example, React Router really rendered & users could live modify the router & that would take effect. But React fundamentally is about using JavaScript state as a model to output html views; it doesnt care about the page. It's a violator of the primacy of the page as declarative source of truth. Ideally all these data objects wouldn't be stored in js stores, but would themselves also be html data islands.
And what a sick abominable horrible thing that would be for the world.
Industrial absolutism definitely has some enticement & draws; you the dev/company have total power & control!
But heavens it sounds like an infernal wicked thing to do, to replace consensus of protocols and standards with each company deciding for themselves how each computer works.
Letting every corporation do low level engineering of their own app platform removes the possibility of inter-working different systems. It is that we have a shared medium that user agency rides atop, that what understandability we have springs from. This is a wildly radical zero-sum pro-corporate wholesale replacement of the interoperable internet with corporate crafted special sauce. It makes the only malleable soft thing in the tech world about us unobservable & indecipherable.
I dream of more than the internet as a delivery platform for closed inaccessible unintelligible illegible foreign systems. Instead of having protocols and standards and media, instead of having a user agent and extensions: what the user experiences would all be dynamic code, it's own engine. It's all a live running self defining universe. No app will have any similarity or prarallel to any other, nor expose hooks; the interface becomes non-distinct, a perfect opaque barrier to the user. Each app brings it's own universe with it, that's what low-level means, and I don't know how user agency or internetworking survive that descent to lower shadowier realms.
It is wild that the long long time HTML editor has decided that RFC8890 The Internet Is For End Users can be shot into the sun, that has decided standards and protocols and specifications aren't worth doing and that industrial supremacy is above all, is the only thing that matters.
There's a long history of the Hixie et Al's Towards a Modern Web Stack being submitted, https://hn.algolia.com/?query=towards%20a%20modern%20web%20s... . Not a huge update here, just a commitment that Hixie is still on this quest after leaving Google.