The design of async/await took "using it in embedded" as a constraint. This is why it doesn't allocate, for example. Even C++ coroutines have one allocation, though they say that it can often be optimized away.

This means RTOS-like projects can use it for tasks, and it works well. Embassy is an example of such a project.

(Yet, I should also point out that you don't have to: at work we keep ours synchronous, for Reasons. Rust lets you do what you want.)

Async/await does not require dynamic memory allocation.