I wonder if it's easier for a compiler/cpu to optimize "async" code ? And I often find myself having an array in JavaScript that calls the same function on each

I wonder if it's easier for a compiler/cpu to optimize "async" code ? And I often find myself having an array in JavaScript that calls the same function on each item in the array, it would be nice if such cases would be made parallel, which I think is possible to do in C++. Is that ever gonna happen in JavaScript !?