Earlier quoted context omitted.
Working in the office is not working on the go. Working on the go is finish up stuff and send it before boarding a plane, or work on that same plane, or during your train commute. If you're going from home to the office and back, I don't see the point in carrying anything other than your smartphone. Talking about the general case, obviously, there are justifications for bringing a medium-sized laptop.
I get things done in all those cases on the setup I mentioned. Obviously if you're taking 8-hour flights then you need that much battery, but is that a common case?
Introduces an extra dependency.