Google uses the os, not the other way around iirc. Manufacturers of phones can of course mess with the os themselves to prevent apks and stuff like that from being installed but once its your property you can just put a new custom os on it and be done with it.
I mean thats not really all that feasible. Android is an open source operating system. You can make a custom os with it.
Can they not require companies to use Google/Apple libraries?
Google uses the os, not the other way around iirc. Manufacturers of phones can of course mess with the os themselves to prevent apks and stuff like that from being installed but once its your property you can just put a new custom os on it and be done with it.