Earlier quoted context omitted.
I've only ever been an Android user, but for a while I was paying a lot of attention to iOS too. It seems to me like they've been back and forthing, as one side figures out some improvements, the other side more-or-less re-implements them on their next release with their own unrelated improvements. Seems like a good thing, really.
Not being an Android user, one of the negatives that was often talked about (maybe no longer true?) is that a lot of phones could not upgrade to new versions of Android. Is that still a thing, or was that limited to the lower tier phones?
Android puts much more emphasis on backwards compatibility, with Google moving more and more functionality into app libraries rather than system frameworks. Our app still supports Android 4.4 (released in 2014!).