End-users DON'T want developers' apps running in the browser to have freedom to access everything on the end-users' machines. Not having direct dom access is a security feature, as much as an MMU is. Please don't ask for this.
Wasm is sandboxed at pretty much the same security boundary as js there is nothing a DOM-enabled wasm module could do (security/privacy wise) that JavaScript can't already do
Except avoid supply chain attacks by not having the shittiest package management system in the current era.