I think this is not about coding style for async code (coroutines vs. callbacks), but about general asynchronity between various processes/threads. If you have

I think this is not about coding style for async code (coroutines vs. callbacks), but about general asynchronity between various processes/threads. If you have any asynchronous background task it means the state of your application can change without the current thread having made any change. And your code needs to account for that possibility, which makes it a lot more complicated.