As well, Javascript's single-threaded execution means blocking execution halts your whole program. IMO, the way to tackle complex asynchronous callback code is

As well, Javascript's single-threaded execution means blocking execution halts your whole program. IMO, the way to tackle complex asynchronous callback code is with smarter code structure and frameworks — just as you should avoid shoe-horning inheritance OOP into JS, you should write async callback code with readability and flexibility in mind (without complaining you "have to" write bad code)