Personally, in JavaScript I like that you can mix and match imperative and asynchronous code using Promise instances. It lets you handle asynchronous control fl

Personally, in JavaScript I like that you can mix and match imperative and asynchronous code using Promise instances. It lets you handle asynchronous control flow in a purely synchronous function. However in other languages, having functions be of a different 'color' is far more painful. In Python for example, a synchronous function has to setup an event loop manually before it can run an asynchronous function. The call works, but nothing is 'running' without the event loop. Additionally, the asynchronous function may have been written to work with a particular eventloop (e.g. trio vs curio), and thus you have to use that type. If non-blocking code has a standardized control state like Javascript, I think it's better to be explicit about async vs sync.