Then you don’t know what you’re talking about. Music, GPS, navigation all continues to run in the background when other apps run, and you can receive - and exit - a call seamlessly.
Sorry, you’re wrong. Spend some time with the device and framework and educate yourself.
Microsofts music, Microsoft's GPS, Microsoft's navigation, Microsoft's phone software -- and only Microsoft's -- gets to do this. The issue is what third-party software is allowed to do. You yourself said all third-party software gets paused. The iPhone allows certain necessary functions to continue.