>I think the only way we could ever get a portable PC experience on the go is by having AR glasses project a full desktop in front of us and let us control it with an imaginary keyboard and touchpad by somehow analyzing our hand movements on a hard surface in front of us.

Or you could buy a GPD Micro PC and save a lot of trouble. It's a full x86 laptop the size of a chunky smartphone, and it's totally practical to use it as a PC.