Is DispatchQueue.global(qos: .userInteractive).async same as DispatchQueue.main.async

Question

I was going through the tutorial : https://www.raywenderlich.com/148513/grand-central-dispatch-tutorial-swift-3-part-1

And came across the definition of QoS class

Answer 1

Anyone who says the .userInitiated global queue is the main thread is just wrong. It's a very high priority background queue, but it is a background queue (and it is concurrent, unlike the main thread).

Apple's own sample code and comments make the matter quite clear:

// This handler gets called on the main thread; dispatch to a background queue for processing.
DispatchQueue.global(qos: .userInitiated).async {

This proves beyond a shadow of a doubt that Apple believes the .userInitiated global queue is a "background queue" and not the "main thread".