The current state of WASM is not really at this level yet. You can't call directly into the browser APIs from WASM, you need a JS layer to do the API call, and

The current state of WASM is not really at this level yet. You can't call directly into the browser APIs from WASM, you need a JS layer to do the API call, and that involves interpreting WASM linear memory. This is slow. Yes, interface-types is supposed to fix this, but it hasn't; it's caught up in a bunch of spec drama, just like the GC proposal. WebGL still requires a lot of API calls per frame; WebGL 2 is better because of UBOs and VAOs, but not substantially. The rust/wasm story is also really bad right now; the latest wasm-pack release has been broken for 6 months now (corrupt release tarball) with nobody interested in fixing it, and wasm-bindgen is practically on life support. Debugging is such a sad experience, too. I regret trying to use rust/wasm, personally.