Unsurprisingly, something along these lines has already sorta been tried [0][1]:
> Famo.us is the only JavaScript framework that includes an open source 3D layout engine fully integrated with a 3D physics animation engine that can render to DOM, Canvas, or WebGL.
They raised a fairly large amount of money, but eventually dropped the idea and moved to a totally different market [2].
Grid Style Sheets [3] gets an honorable mention as well. It compiled GSS rules and applied them as fixed position divs.
I've been researching this subject a bit lately. Surprisingly, many of these problems were already solved in the native world by the end of the 90s. The key innovation from the web is that it's a fully sandboxed environment.
Despite all the web's flaws, one area in which it has done pretty well is accessibility. Many native apps leave a lot to be desired when it comes to basic accessibility... Heck, that goes for many "modern" web apps as well. Hopefully browsers expose good accessibility APIs by the time your vision of developers shipping their own rendering engines becomes reality.
[0] http://deprecated.famous.org
[1] https://github.com/famous/famous
[2] https://techcrunch.com/2015/11/06/nopen-source/
[3] https://github.com/gss/engine