You can probably optimize JS to run as fast in most cases. What actually WASM brings is predictable performance. If you're JS wizard, you can shuffle code aro

You can probably optimize JS to run as fast in most cases. What actually WASM brings is predictable performance. If you're JS wizard, you can shuffle code around, using obscure tricks to make current browser to run it really fast. The problem is: JS wizards are rare and tomorrow browser might actually run the same code much slower if some particular optimization changed. WASM performance is pretty obvious and won't change significantly across versions. And you don't need to be wizard, you just need to know C and write good enough code, plenty of people can do that. Clang will do the rest. I agree that using WASM instead of JS without reasons probably is not very wise. But people will abuse everything and sometimes it works out, so who knows... The whole modern web was born as abuse of simple language made to blink the text.