Async await is a different concept to structured concurrency. It just allows that two async tasks can run on the same work thread, but it doesn't directly give you access to do so. That's what goroutines, task spawn methods or structured concurrency give you.

At least in rust, calling an async function won't do anything by itself. It must be spawned or awaited. However, I wouldn't be surprised if other languages spawned on every async call and the await was just a join handle.