I used to think so, too, but on the one hand, the DOM API is absolutely massive. Going through the standardization, implementation and documentation process another time would take decades.

And on the other hand, a language-agnostic API in WebAssembly would mean specifying it WebAssembly itself. And well, it's Assembly-like, so what's currently a single line for calling a JS function would turn into tens of lines of low-level code.

Ultimately, you'd want code from some other high-level language to give you a summary of how you may need to call your language-specific wrapper. In practice, that's likely even worse than translating it from JS, because the high-level call isn't standardized.