They were not forced to do it because of their OS woes. They just did the correct thing.
Apple's not doing the correct thing. SwiftUI just created a barrier where people pre-iOS 13 lose access to a lot of apps, and those apps will be raising their minimum version a lot more often than before. So if anything, you could consider this a ploy by Apple to get people to upgrade their phones.
Nope, if Android updates were a reality, there was no need to ship a system library with the application.
That is the whole point of Jetpack libraries, to ship newer versions of Android with the application, with polyfills, as the OS updates will never happen.
Apple's not doing the correct thing. SwiftUI just created a barrier where people pre-iOS 13 lose access to a lot of apps, and those apps will be raising their minimum version a lot more often than before. So if anything, you could consider this a ploy by Apple to get people to upgrade their phones.