what is the main benefit of using coroutines instead?

non-blocking code? 🙂

@deviant RxJava and Reactive Streams also facilitate writing non-blocking code. I was trying to ask what coroutines will do better. I think I understand better now.

rxjava still uses callbacks/futures concept. when you use it synchronously it still blocks the thread. coroutine can suspend the running code context without blocking the thread.

that's not quite accurate, if your using callbacks on a future then you are using it synchronously (in that A happens before B), but it is not blocking.

sure. but who wants callbacks hell when we have coroutines?