Obviously this was just one example to demonstrate the convenience of VR/AR over smart phones. You would not be using VR/AR for "just that one thing". The applications are numerous:

* Ability to have virtual workspaces with multiple high-resolution simulated monitors (and that's just the low-hanging fruit of simulating existing workspaces at a lower cost and more portability, it is entirely possible that VR will lead to completely new workspaces. But let's be a pessimist and assume simulating existing workspaces is the best we can do.). I mean if VR can deliver this one thing and nothing else, I would say it will be a huge success.

* Ability to read/work on commute without getting a headache from vibrations (since the image will be stable)

* Lifelike interaction with friends and family in a moment's notice and no air pollution

* Videogames

And these are some of the easier and less speculative uses of VR.