Have you actually tried it? I haven't seen a link to try it. We built https://ayvri.com, and we use WASM extensively (though the public site is using cesium, we've also built our own renderer which is not public).

Also, the original blog isn't only about WASM, that's just one of the technologies making this sort of thing possible.

Canva was built pre-WASM, so photoshop in the borwser, may be better with WASM, but I'd suggest it isn't a requirement.