Very interesting observation. Is that the end game? An iPad Pro to rule all? It can be docked on a nice stand, powered from the mains for more performance and charging when required, docked to external monitors when needed. Now they have chip parity across the line, what stops this from happening?
Who said it is stopped from happening?
It's happening right under our eyes, at a slow pace, because you can't just make so many changes in terms of software, ui, perspective, etc.