I’m genuinely confused by these responses. It’s as if most didn’t actually look into what WASM was besides a cursory glance and then answered right away.
First off WASM is (relatively) new. It’s at 1.0 which iirc is basically an MVP product. It will take years for all browsers to integrate it appropriately.
Why choose WASM over JS? You probably wouldn’t right now unless you wanted to help pioneer the technology. Again it’s fairly new and probably not expected to be used in professional environments yet.
As for the benefits, it’s mostly the speed of code execution. Yes JavaScript is fast and robust enough for current web apps. No it is nowhere near as fast as native code.
Think about PC games. When people need performance, JS is definitely not the first option or even one of them in most cases. You want a language closer to the metal which is why compiled languages like C++ are often used.
All that said, if it was in a mature phase and did run faster than JS, why would you care? Well with native compiled code, you could run some hefty programs from a browser with the speed of native code.
That potentially means running more intensive applications like games and photo editors completely on a website. You could bypass the need to download software. You would visit the website, the WASM code would be sent over and used in the browser to run the application.
You can also interact directly with JavaScript via a WASM and call WASM functions within JavaScript so it’s pretty connected.
Overall it’s a fairly new technology that when matured could mean a major change for how the web works. It will likely be a long time until we see it capable of being used professionally and even longer before we see widespread use.
How ironic that the article talks about dark patterns but as soon as you visit the webpage you get a cookie disclaimer whose reject “button” is small text tucked away in the top right of the modal.