I would assume it's more about making it more convenient for developers to build an app for iOS and macOS using similar frameworks and APIs, without depending o

I would assume it's more about making it more convenient for developers to build an app for iOS and macOS using similar frameworks and APIs, without depending on React Native or just throwing Electron and the web stack at the problem. From my own minimal experience you have to pull in a fair few dependencies or do quite a lot more work if you want a more modern look for a native Mac app. Additionally, if I want to bring an iOS app to the Mac, then it'd be great to not have to figure out the Cocoa version of a certain UIKit view and then rewrite all of the code to fit. I can't imagine this would translate to some next-level version of universal binaries, but who knows what it'll be like in a few years.