JavaScript's one advantage was that it was the privileged language in the browser. It has lost that now.

JavaScript has entered its Walking Dead phase. It will gradually be displaced by all languages compiling to WebAssembly.

JavaScript’s main advantage is being commonly familiar to most software engineers.

The English language similarly lost its position as the preeminent imperial language a long time ago, so too with Latin & Rome. It takes a long time for a popular language to die because everyone wants to speak what everybody else speaks.

WASM has a lot of shortcomings. You can't even update the DOM without doing a worker dance.