Looks like you need nested virtualization for running windows xp apps within the new newer windows systems. I'm also curious about other uses for it. Why is it

Looks like you need nested virtualization for running windows xp apps within the new newer windows systems. I'm also curious about other uses for it. Why is it a must have when you could technically just use a virtual windows xp system. I guess running a legacy application in a more secure and newer OS?