Why does it make sense to compare it to HTML, CSS and JavaScript?

You could say "Granted, there are those who use the webcam capture API, but if we compare it to HTML, CSS, JavaScript, then the webcam capture API is simply not existing anywhere near that level."

Like how not every website needs to use a webcam, not every website needs to port existing code to the web or accelerate heavy computation, which is what WASM is meant for... that doesn't mean it's not useful for ones that do. It's not supposed to replace any of HTML/CSS/JS