Less space required. Not limited by the size of your workspace. Trivially move your workspace. Get more "screenspace" at the click of a button instead of having to spend $$$. Power efficiency.

Think about where this will be in 10-20 years, not where it is now. It will be like putting a pair of glasses on, not a huge headset. Once your workspace can exist in 3 dimensions, new paradigms will emerge for arranging a "desktop" that we can't even envisage right now.