Async/Await is finally back in Zig

All the stunts in async/await or goroutines in go stem from the fact that there is no support for something lighter than posix threads in kernel.

Shouldn't the OS kernel innovate in this area instead of different languages in userland attempting to solve it?

Fair. The languages have to come up with something based on APIs that were not meant for that, like io_uring, etc.