[zelphirkalt]

I think you are mixing up lots of stuff or at least write about them in a misleading way.

Python has async, has green threads, and has OS threads through the multiprocessing module. The fact that it has the GIL does not mean, that it cannot use OS threads or multiple processes. JavaScript in comparison does not have multithreading. NodeJS itself is multithreaded, but you cannot put application computation on those threads. You will need to use worker-threads and basically like PHP run multiple instances.

However, neither of those languages is particularly nice for using the multiple cores available in modern machines anyway.