I should have specified that better, of course async and await can be lowered to different things (that's what Zig does afterall), what I wanted to say is that that's how it works in general. JS is a good counter example, but for all other mainstream languages, async means stackless coroutines (python, ruby, c#, rust, ...).
Which means that if I want to use a dependency that uses async await, it's stackless coroutines for me too whether I like it or not.
