I suspect the split between iOS and iPadOS was about slowly moving iPadOS closer to the mac ("what if we made a desktop OS based on the iOS app security sandbox

I suspect the split between iOS and iPadOS was about slowly moving iPadOS closer to the mac ("what if we made a desktop OS based on the iOS app security sandboxing model?") Meanwhile, they have been moving macOS to have more of the libraries and look and feel of iPadOS, and having catalyst be both a build target for making mac apps, and to reuse the libraries for running iOS/iPadOS-compiled apps on M1. So I don't suspect they use it for anything like virtualizing macOS - they seem to instead be trying to build that part of the bridging functionality into the mac. I suspect instead it is about giving the Pro model enough head room for more serious porting of "pro apps" to the iPad.