I would take these benchmarks with a pinch of salt. Within a single function, it's very easy to optimize JS because you know every way a single variable will be defined. When you have to call a function, the data type of the argument can be anything the caller passes to the function, which makes optimization far more complex.

In practice, WASM codebases won't be simply running a single pure function in WASM from JS but instead will have several data structures being passed around from one WASM function to another, and that's going to be faster than doing the same in JS.

By the way, if I remember correctly V8 can optimize function calls heuristically if every call always passes the same argument types, but because this is an implementation detail it's difficult to know what scenarios are actually optimized and which are not.