It's not to free the hands. The primary reason to go for this interface is comfort and ergonomics. Holding up your hands in the air for prolonged amounts of tim

It's not to free the hands. The primary reason to go for this interface is comfort and ergonomics. Holding up your hands in the air for prolonged amounts of time is hard. We use keyboards and mice because we can rest our hands with them. Apple's approach avoids that and lets your eyes do the selection, while still using your fingers for the clicking, thus giving you the responsiveness you are used to (i.e. no weird "hover over icon for one second to active"). Also according to people that tested it, it feels extremely natural, basically like mind reading, since the moment you look at something, you can click it. There is no separate step where you have to look at something and then also have to navigate your laser pointer over it to activate it. As for passthrough, I think that will become extremely useful and commonly used when combined with the depth sensor, as it allows you to partly fade in and out pieces of reality. You can have a virtual office on the moon, but the desk in front of you, is still your actual real desk, while all the displays on it are virtual.