This is an idea which in broadest sense sounds impractical to me. Partly because, most of the work can be stored in the cloud right now, and most smartphones can run any productive app required to work on those.
Another reason is, the idea itself is self contradictory, in a sense. You require a bigger display to work on with this, which's what usually happens in a normal way too. You do some work on your PC and put in on cloud, then you can edit it on whatever platform you want. What's so different with doing this on your cellphone connected to a bigger display with a hub to act as mediator?
Now I do agree phone can do many a tasks fluently, and with a bigger display that might even be done better, but there are some things which a phone won't really be best at doing, 3D modelling comes to my mind first, your really do require a PC or laptop for that. Just to add some salt, virtual reality is very much present in the near or distinct future.
Not being too critical, it's a fairly impressive idea, but in my honest opinion, of little practical purpose.