Call recording used to be easy to implement, until Google took a look at the obvious security problem with apps recording calls from the background, and restricted the normal APIs to system software only. If an app has automatic call recording that works well, the manufacturer probably put an insecure OS on the phone, because then any app or game you download probably has that capability.
The supported APIs all have excellent backwards compatibility through AndroidX. You can still many if not most modern APIs all the way back to Android 5 without much change in the code. Most system APIs are backported through Google's libraries, and for many others the standard compat library has shims that avoid most version checks. This is sort of the opposite of iOS, where most users are updated within a few months so many years of backwards compatibility isn't a big priority.
Cheap, slow, crappy devices and background task killers are much more of a problem than the problems plaguing a lot of the APIs.