I think this is why the makers of Ubuntu have been trying to get their system to run in parallel to Android phones on their hardware. Imagine the phone you carry around being able to be dropped into a docking station and run 2 monitors and a keyboard/mouse on a full desktop OS.
I definitely need two or three monitors to get my work done, but increasingly it doesn’t really matter what form factor of device is plugged into them. One of my monitors is hooked to an E350 desktop case that could just as easily be an android device, as I mainly use it for logging into other systems and web browsing. Another monitor switches between being a secondary for a PC and running various console devices.