Big Sur has been moving closer to the look and feel of iPadOS so that the new Apple Silicon machines can run iOS-native apps under catalyst without it being too jarring a difference. They greatly increased the amount of code in catalyst to make this possible as well.
At the same time, they have been adding Mac features to iPadOS to make it easier to make a full-featured iPad app closer to a proper featured Mac app. One example there would be mouse/trackpad support. Another would be the multitasking support which, for all of its UX weaknesses on use, makes variable sized, multi window applications available on both platforms.
Messages is an example of the medium-term game Apple is playing here. I anticipate a large number of the built-in apps to be (finally) a single code-base under a single team. They are gaining more capability to do easy, deep customization per OS in each release - but also seeing the systems themselves move closer in terms of UX feature set.
> Big Sur has been moving closer to the look and feel of iPadOS so that the new Apple Silicon machines can run iOS-native apps
Look and feel has little to do with the ability to run apps. The primary reason Apple Silicon will run iOS apps natively because it will be the same processor architecture.
However, a desktop OS being shoehorned into a mobile-like design is a very bad thing for a great amount of extremely obvious reasons.
At the same time, they have been adding Mac features to iPadOS to make it easier to make a full-featured iPad app closer to a proper featured Mac app. One example there would be mouse/trackpad support. Another would be the multitasking support which, for all of its UX weaknesses on use, makes variable sized, multi window applications available on both platforms.
Messages is an example of the medium-term game Apple is playing here. I anticipate a large number of the built-in apps to be (finally) a single code-base under a single team. They are gaining more capability to do easy, deep customization per OS in each release - but also seeing the systems themselves move closer in terms of UX feature set.