I guess it depends on what OP is talking about. Async code can be written with callbacks (callback hell incoming), or with Futures/Promises, or with syntax sugar like async (do notation).
Whatever the reason is for using async, I believe that the mismatch happens not because Async is optimized for I/O bound programs but because it's insanely easy to use (in Rust, Javascript).
Whatever the reason is for using async, I believe that the mismatch happens not because Async is optimized for I/O bound programs but because it's insanely easy to use (in Rust, Javascript).