Asyncio is annoying, and often unexpectedly slow. You think things are parallel, but then one misbehaving coroutine can hog your cpu bringing everything to a halt. GIL makes it useless for anything other than _heavily_ IO bound tasks.

And yeah, Python's documentation is useless. Never how to use stuff, only listing of everything that's possible to do / the API. Unfortunately that style is being mimicked by most other Python projects as well.