Remember "callback hell"? Assumption that a function call returns after running to completion requires rather specific synchronous cascading architecture, which WILL break in multithreaded code. Most of the multithreaded function calls will set a flag in shared memory and return early, expecting caller to poll.

If your API is based on single entry-point `invokeMethod(callee, method)` it is equally untraceable to event entry point `fireEvent(producer, event)`.

  const
    myEvent = 'myEvent', 
    target = new EventTarget()

  target.on( myEvent, () => {
    console.log( "It's easy to introspect well-organized code." )
  })

  target.dispatchEvent( new Event( myEvent ))