The article seems to evaluate Wasm as it were a framework upon which apps are built. It's not that, it's an orthogonal technology allowing CPU optimisations and reuse of native code in the browser. Against that expectation, it has been a huge success despite not yet reaching bare-metal levels of performance and energy efficiency.
One such example: audio time stretch in the browser based upon a C++ library [1]. There is no way that if this were implemented in JS that it could deliver (a) similar performance or (b) source code portability to native apps.
[1] https://bungee.parabolaresearch.com/change-audio-speed-pitch
Yes there is, WebGPU compute shaders, or misusing WebGL fragment shaders.
>despite not yet reaching bare-metal levels of performance and energy efficiency.
"Not yet"? It will never reach "bare-metal levels of performance and energy efficiency".