I suspect some of this is why more recent DJI drones have an OS and screen on the controller, because that way they have a single set of hardware to target, and

I suspect some of this is why more recent DJI drones have an OS and screen on the controller, because that way they have a single set of hardware to target, and even if some future Android release breaks backwards compatibility they can simply choose not to update to it and the controller will still work.