I think I don't want a laptop, but the only thing preventing me from getting the most powerful iPad is Apple policies, you are right, when you put a keyboard on the iPad it weights as much as your MacBook Pro, but then the tablet is on his desk, and the ability to remove it and just use it in the bath to read something, or to hang it to a iron arm and watch a video are not that easy with a MacBook, as soon as iPad supports virtualization and proper development workflow I am sold, I go and never come back to laptops (but I don't have laptops, only the work one)
Another potential benefit of the iPad over macOS alternatives: you can get a waterproof case for an iPad. There’s just no easy way to make a macOS device waterproof.
As for virtualization of other OS on iOS: already exists!
Beware - performance isn’t great and you can crash your iPad (I’ve don’t it — it was quite scary as I had never seen that happen). The iPad just doesn’t have enough memory to make running a VM a viable option for coding on an iPad, even an iPad Pro.
(My experience from a few years ago on an iPad Pro 12.9).
I think it could happen given legislation allowing easy sideloading of apps and competition on app stores, and maybe a production simplification where it would make sense to use the same CPU on both Macbook and tables
