It is not nearly as much of a problem in JS because JS only has an event loop, there is no way to mix in threads with async code because there are no threads. Makes everything a lot simpler and a lot of the data structures a lot faster (because no locks required). But actual parallelization (instead of just concurrency) is impossible[1].

A lot of the async problems in other languages is because they haven't bought up into the concept fully with some 3rd party code using it and some don't. JS went all-in with async.

[1]: Yes I know about service workers, but they are not threads in the sense that there is no shared memory*. It is good for some types of parallelization problems, but not others because of all the memory copying required.

[2]: Yes I know about SharedArrayBuffer and there is a bunch of proposals to add support for locks and all that fun stuff to them, which also brings all the complexity back.

In my less charitable moments, I've wondered if the real reason Python has async/await is because people coming to it from JavaScript couldn't be arsed to learn a more appropriate paradigm.