A lot of comments suggest there is a bigger difference between the iOS and macOS code bases than there really is. iOS was spun off from OS X (now renamed macOS). It is the same code base.
Here is an example: Xcode is the development environment for every Apple OS. It includes an app called Simulator. This allows a developer to test iOS apps on a Mac, simulating the screen, etc. of a chosen iOS device. To do this it compiles the iOS app to work on Intel. The programming languages most commonly used are processor agnostic. The main differences are in the APIs for how sandboxed the apps are, how the file systems are accessed, and how the users interact.
Another example: More than half of all mobile games are made with Unity (including the ones I am working on). To make a Unity iOS game work on Mac is a matter of selecting the target platform. The actual work comes from making it suit Mac screens and input types. That is easier for some than others, but many do not bother because the market is just not there.
The big difference between iOS and macOS is how you interact with it. iPadOS has blurred the lines by having both control options, but Apple's repeated remarks that touch does not suit Macs has not gone away. I don't expect the iMac to become a touch based device in anyway.
That isn't to say there will not be more crossover, extending what they have done with Sidecar. I'm surprised there isn't already an official cradle so an iPad can act as a large Magic TrackPad, with the added abilities that the screen would allow. I could see a larger desk based iPad as a result of this to make an excellent alternative to a Wacom drawing tablet.
Great post. I really enjoyed reading that and the nuances of where the 'state of the universe' is and why the next transition will be a lot easier than the last one. Chances are, Apple has already Mac ARM running MacOS/iOS in their labs on an A12z or A13 and 'quite surprised' by the results of it. It may explain, partly, the leisurely nature of Mac hardware updates.
Apple are so much further ahead in this transition already. The Mac and iPad are fundamentally the same. Marizpan is just translation of the 'top layer' APIs for the target platform. Resolution. Interface elements? With each iteration of Marzipan...the 'translation' into a 'Mac' app becomes simpler for the developer in terms of the more mundane elements such as interface, resolution...and the under lying code compile.
Those lines are indeed getting blurred with iPad's 'interactive' elements eg. mouse/trackpad/keyboard support.
It's less about the iMac becoming an iPad and more about an iPad becoming an 'iMac' over time. Just as the iPad has morphed into a pseudo laptop. The iPad will be all the desktop many need if it reaches 16, 21 or 27 inches in size. It becomes Son of iMac just as Mac was Son of Lisa...or iMac was Son of Mac.
It's largely semantics in terms of how it gets there...the destination seems to be the same.
For many reviewers, the iPad is the best Wacom they never made. And for me? The iPad is the best 'Mac' Apple ever made. A true fulfilment of a computer for the 9 out of 10 tasks 'rest of us.'
It's still got a ways to go and that's where Mac ARM comes into play.
A larger desk based iPad is (for me) the true evolution of the current iMac. The interim goal is 'side car' but the ultimate goal is insurrection.
A 16 inch iPad running Logic or Final Cut (will they debut THIS year or next year with the Mac Arm?) will make a massive transitional step to Mac ARM. I'd love to run Procreate, Affinity Photo and Design on such a device.
But ultimately, a 'desk based' 21, 24 or 27 inch iPad is where I'd like to be. By then, 'Mac' ARM will be a reality.
Azrael.