If JS had native SIMD, probably. But it doesn't, and it won't (because it's complex to do in JS, and you can just use Wasm instead), so it really can't compete because of just how much faster Wasm can be these days.
It's not for lack of trying either, there was a JS SIMD proposal which got pretty far along, but then everyone came to their senses and scrapped it to focus on WASM SIMD instead.
That's a bit of a trick question - typical use case for each is different, you don't use these interchengably, it doesn't make that much sense.
Typical use case for JS is let's say a glue between network and DOM, where it doesn't really do much, most of that work is done by the browser anyway. If you add wasm to that, you'll just add one more indirection through the wasm sandbox and it'll probably be slower in many cases, because you have to copy data.
Typical use case for Wasm is either porting existing native programs or something compute heavy. Figma uses this for the native layer, I used it for some image processing use cases or for board game solver backend. Doing that in JS is slower because JS semantics are not straightforward to optimize, even for basic numerical operations. I found something around 3-10x speedup for this kind of code is pretty common, but it depends on what it is doing - whether JS can represent the types and operations well.
