To be fair to that guy, the Python standard library provides a multitude of incompatible takes at async already, none of which covers all common use cases. The newest take (asyncio) doesn't integrate with external event loops, so unlike similar libraries in C# and Kotlin, it doesn't work with GUI libraries, not even the one in the standard library (tkinter).
The third-party asyncio alternative Trio, on the other hand, has recently added "guest mode" [1] to plug in external event loops, so maybe that will become the one true way to do async.