Eh, my gut tells me it will look more like the 3D TV market when it comes to scale. Smart phones have way more main-stream utility than anything AR proponents have come up with IMO.
Replacing secondary monitors will be the business case for AR/VR near term, but everything will go this way. The digital and physical worlds are already merging.
Do you really think in 100 years, everyone will be carrying around a tiny screen that acts as a portal to the digital? Or will the digital float around the physical world.
Neither myself, nor anybody else, has truly accurate insights into how humans will interact with tech in 100 years. Predicting the future is damn near impossible. I agree we probably will not be using the smartphone form, but I disagree that it will be replaced with something sprung from the current iterations of AR/VR. Again, id bet money on the adoption being similar to 3D TVs. Cool tech, not practical for mass adoption.
How many people wear glasses?
If you haven't tried the Hololens2 you haven't the context to evaluate the potential for the tech. I let my non-technical sister try it for 30 minutes and her response was "This is so cool! I'm going to go tell my friends I just tried the future!"
There are plenty of professional use cases for AR. Having a HUD or contextual menus next to physical objects will be highly useful. Doctors, assembly, construction, factories, navigation... the list is long. The Snap device is a much cheaper, though limited by comparison, device and people are finding uses in fitness.
Also, with no more need to have touch screens on every device, the cost savings will be huge