Well that's because AR and VR are strictly worse for most use cases as compared to traditional human computer interfaces.

The mouse, keyboard, and monitor is pretty much just right. Highly productive, you can go super fast, with extreme information density.

VR and AR are obviously much slower to navigate because physical worlds are slow to navigate and that's what they're mimicing. We might assume a 3D world has more information density than a 2D screen... But 90% of the time it doesn't. I don't have eyes on the back of my head. And, usually, I'm going to be staring at a 2D thing.