As far as I'm concerned the "big iPhone" idea is a failure. I don't want a tablet that doesn't have the full power of a PC OS like macOS or Windows. That doesn't preclude touch. The OS and apps could and should be updated to support touch. And Apple has the market power to pull that off.
I want an OS with the full power of a PC OS + touch. You can get there by taking a mobile OS and making it more powerful, or by taking a PC OS and adding touch to the OS and apps. Yes, both options require a lot of work, but Microsoft is further ahead in having shipped it for years rather than denying the problem, as Apple does.