That's interesting perspective, and I can easily imagine something like this:Someday, there will be an 'Xcode' for iOS that will allow developers to work entirely on iOS (Swift Playgrounds is already starting to get us there). But I don't see it stopping at just 'Xcode for iPad' - Apple could very likely introduce its own 'build-code-as-a-service' thing, which would allow developers to easily develop on an iPad locally, but the actual compiling, packaging and distribution of binaries would be all handled by Apple...
- Apple introduces/adopts an innovative new way of programming apps for its "ecosystem" (think HyperCard, LiveCode, Visual Basic, but something newer).
- Your code is stored in Apple's cloud (think Github, now owned by Microsoft).
- Apple "compilers"/processors helps you write, run, and debug your code in the cloud (e.g. in virtual machines) while doing security checks and preparing the software/product for Apple distribution.
- Apple leverages its untold billions of intimate customer details, along with its AI technologies, to prioritize software and developers within its system for maximal profit.
- Apple leverages its billions of customers, its own software, its App and iTunes Stores, and all the advertising channels involved in those to sell and profit from an ungodly amount of content created by others.
- Apple adds new media businesses (video, periodicals), and their advertising channels and influence, to its existing Apple Music, Apple TV, iTunes, App Store, etc. to market more powerfully than it ever has before.