I'm not sure how it works in all languages, but in Python you have to deal with errors in a try/except block. In general the way you handle errors that happen on "blocking" async calls is by wrapping in a try-catch style syntax and handle the error. How would you handle the error otherwise?

You can handle asynchronous code in JS in four ways: callbacks, Promises, generators, and async/await. In the former two, errors are dealt with in a non try-catch way, to the programmer, because either you pass the error as the first callback parameter, or the VM handles error passing for you and you deal with it in a catch block. The latter two you must wrap code that may fail in a try-catch block (or just not handle the exception). You can stick with callbacks, but it's generally easier to read well written Promises, and in a lot of cases async/await make it even clearer. The only time that it can be confusing or difficult is if you want to do multiple await calls simultaneously.