The most advanced user interface for AR /XR headsets aren’t made by a Silicon Valley tech company. They are the F-35 HMDS (helmet mounted display system) they cost almost $500K and have 360 view of the entire aircraft. Each helmet is custom fitted for the pilot, with sensors, display etc 

It is an engineering marvel

creating and destroying; built flying cars & autonomous vehicles, now building /faust, more here: /july, web: july.rocks

I wonder how much that $500K price tag could come down if someone like Elon took a hard, first-principles look at the cost of components and integration