For me, when I use python, it's because I want faster dev time to prove a concept or that I expect others with little to no programming experience to maintain the code in the future. So, I rarely ever use async because I never seem to be in a position where the debugging complexity and how hard it is for others/newbies to read and be familiar with the code is worth the performance improvements.

Like others are saying, if I want it fast and efficient (processing), I'll just use Go. Python isn't like JS in browsers, you don't have to use it, you have to want to use it. and the same goes with its features. Maybe if python tutorials/books and "How do i ____ in python?" search results used async, map, filter, collections,etc.. these awesome python features would be more prevalent. But, I can see how mature projects should probably mandate their usage where it makes sense.