Earlier quoted context omitted.
One couldn't, because you'd need to standardize a JS-less DOM, which requires one to persuade Apple, Google, Microsoft, and Mozilla to agree on a new standard for a JS-less DOM API. The DOM API is currently defined as a JS API, including JS strings, JS objects + properties, JS Exceptions, JS Promises, JS garbage collection, and on and on and on. The effort to get all the browsers to agree to standardize a new JS-less…
Web API is described in WebIDL, and javascript has its own approach to consume these interfaces.
The issue is that many modern DOM APIs assume js semantics and types (eg promises, iterables, etc) so you need to "reimplement" some js semanthic in wasm; sorta like how apple added a few custom instructions on the M1 chip specifically for the type of floating point operation required by js.