> The main benefit of having async (or Go-style M:N scheduling) is that you can afford to launch as many tasks/fibers/goroutines/... as you want
Some have argued that the real solution to this problem is to "just" fix OS threads. Rumor has it Google has done exactly this, but keeps it close to their chest:
https://www.youtube.com/watch?v=KXuZi9aeGTw
https://lwn.net/Articles/879398/
Somewhat related and also by Google is WebAssembly Promise Integration, which converts blocking code into non-blocking code without requiring language support:
I see a possible future where the "async/await" idea simply fades away outside of niche use-cases.