JavaScript was always single-threaded asynchronous, the added async/await keywords were just syntactic sugar. Node.js became popular before it as well, though I found at the time it was difficult to avoid callback hell similar to using libuv directly in C.

async/await was syntactic sugar in C# as well. Callbacks are a natural way to do async so it's no surprise.

And while Python implements async directly in the VM, its semantics is such that it can be treated as syntactic sugar for callbacks there also.

async await is syntactic sugar hiding calls to poll() and callbacks in every programming language.