[littlestymaar]

You can indeed avoid most of the js overhead if you use a particular subset of the language. In fact, that's how asmjs started, but:

- it's not JavaScript anymore, you'll lose most idioms you're used to work with, and it's a nightmare to maintain because it's pretty low level.

- it won't be as fast as it could unless the runtime is aware of the fact that you are using that subset (that's why asmjs used some annotation to run on a special engine on Firefox, and part of the reason why browsers moved to wasm).