Well, I have to admit, the iPad Pro is not for everyone; your three points are very valid ... for you.
I mainly got the iPP for the large scree also. And that is wonderful. I have old eyes and any time I can make my view larger is a GOOD thing.
I also agree with you that the side-load feature could be more useful - mainly cause I want the ability to decide what apps appear in the side list. I hate scrolling for the one app I want cause usually it's at the very top of the list. And, it'd be even better if all my apps were given the side view capability.
Oh, and I'll be a real happy camper when all my apps use the new Pro keyboard (Tapatalk - I'm talking to YOU).
I can only hope developers are hard at work on this. But, oh, when I can copy a picture in Photos in side view and then paste it right into Keynote, all without having to do any swiping or closing/opening apps? Heaven!
I did find a calculator that does have side view access: Calculator Pro for iPad (Calculator Pro for iPad - Standard and Scientific Calculator by Apalon Apps
Calculator Pro for iPad - Standard and Scientific Calculator on the App Store).
So, obviously, I'm in extreme like of my iPad Pro. Maybe give yours that week and see if it "grows on you"?
Hope this helped.
Marilyn