I travel A LOT for work. Portability and power are key when I'm on an airplane, cranking out lots of email over breakfast, etc... the perfect companion to my MacBook Pro, an iPad Pro could replace some of its functions, be light enough for the plane work, and have battery to make it through.
I'm even toying with connecting it via Remote Desktop into a new virtual system we are setting up at work... The bigger screen will give me some better real estate in that system.
Granted I can do this with the MBP, but there are times when the size, weight, and battery make that inconvienent. Plus immediate always on!