I'm more and more thinking that JS is heading in the wrong direction. I'd opt for splitting up JS into two; one is a low level compilation target, something like... I forgot the name now, it was a subset of JS with hints in comments that allowed the interpreter to forego certain checks (mostly around the dynamic nature of e.g. objects) for speed, I believe this predated WASM and co.

Anyway, a simple version of JS or more like bytecode. Then developers can pick whichever language they want. Because these type annotations do not benefit execution, only development.