If you reimagine HTML, CSS and DOM around web applications, you'll lose everything that make them great for their original purpose, which is rendering (non-fixed-layout) documents and structured content.
Surely there are some hiccups left in the design that come from its organic growth and could be smoothed out; but those are not as much as you would think, and most of that work has already been done in html5+ES6.
The end result is a platform that is great for zero-install distribution of web applications AND web documents. A new framework that centered only on the first goal would be severely limited, and a new one that served for both would look a lot like the current one.
Surely there are some hiccups left in the design that come from its organic growth and could be smoothed out; but those are not as much as you would think, and most of that work has already been done in html5+ES6.
The end result is a platform that is great for zero-install distribution of web applications AND web documents. A new framework that centered only on the first goal would be severely limited, and a new one that served for both would look a lot like the current one.