Sorry (not sorry) — not sold on this replacing of both devices.
Look — I get that we’re all our own use-cases and like to act as if we are the intended target of every new devices that comes out. We believe that our feelings are universal and shared by all.
Not true.
I use a Surface Book for the simple reason that the vast majority of the time I need a laptop and far (far) prefer typing on real keys. If (and that’s a big “if”) I need a tablet, I can just pop the screen off. One device, 2 form factors. Perfect (for me)