Async/await is not a solution to poor thread models.
Async/await is cooperative multitasking and is no help at all for cpu bound problems.
For i/o intensive systems it makes non-blocking i/o look like blocking i/o, and people find that helpful.
I do real-time i/o so I need more control and Async/await is unhelpful.
It is a worthy adition to Swift I agree. But they sorely lack Rust's excellent design in this area