VMs are needed by professional developers who want to run CLI tools and services (e.g. web server, database) without the security restrictions of iOS, while retaining the OS integrity of the iPad Pro device.
Even if a macOS VM had only a CLI terminal and a few core apps made by Apple, using a Swift UI framework that was compatible with a touch interface, it would be a huge step forward for iPad owners who are currently limited to slow and power-expensive emulation (iSH, ashell). Apple could create a new app store or paid upgrade license entitlement for iOS-compatible macOS apps, so that users can pay ISVs for an app version with iOS touch input.
What you’re talking about sounds great but it’s not “a touch optimized version of macOS”. You’re describing a CLI environment in a sandbox.
Apple will never ever take macOS and change its UI to be optimized for touch. Or at least if they do, it’s time to sell the stock. They already have a touch UI, and it’s called iOS. They’re converging the two operating systems by making the underlying frameworks the same… the UI is literally the only thing they shouldn’t converge.
The mythical convertible iPad Pro "docking" to a "MBP Base" to use it as a touchscreen. ;)
I like the fact that a number of iPad and iPhone apps now run on macOS without a simulator or any ceremony. While they are touch-optimized, they're easy enough to use with a pointing device. The gotcha to such mythical OS convergence is the inverse is untrue since a desktop UI is unusable 1:1 on a tablet with the coarser granularity of tapping and less keyboard access.
Perhaps OS-level AI in the future will be able to automatically follow design guidelines and UX rules and generate a usable UI (Storyboards or such View parts) on any platform given a description of data, its importance, and a description of what it should try to look like.
Even if a macOS VM had only a CLI terminal and a few core apps made by Apple, using a Swift UI framework that was compatible with a touch interface, it would be a huge step forward for iPad owners who are currently limited to slow and power-expensive emulation (iSH, ashell). Apple could create a new app store or paid upgrade license entitlement for iOS-compatible macOS apps, so that users can pay ISVs for an app version with iOS touch input.