In my experience, the bigger issue was designers assuming everyone has the taller iPhone 5 screen size (or worse, iPhone 6) and burning up 95% of the screen with keyboard + giant fixed header + fixed footer. Some apps would give you space for maybe two lines of content in between all that.
More of a complaint with 3rd party devs on that though.
Also the "cherrypick" comment is a bit of a dodge - Google already does security patches for older releases (3 years vs. 2).
It would arguably be just as easy to secure one codebase and pare features down for performance.
So I do commend apple for getting updates to that device for 4 years, but at least in their experience, it made the phone worse and didn't bring all the features that they wanted.
As I recall all those features were built only for 64bit CPUs which the 4s/mini didn't have.