In my view, the DOM is too cluttered and bloated, difficult to work with if you're a browser. There are a lot of things that should be made deprecated, but it's difficult to decide which things, since big browser are usually rivals (apple, google, microsoft, mozilla...).

Browsers are already pretty complex machines, considering javascript and the DOM and everything that comes along. Expecting all browser to let WASM have access to the DOM is a big demand.