CarPlay and Android Auto aren’t car OSes though, they’re merely an infotainment interface. You still need a way for the user to check the tire pressure, choose between sports mode and eco mode… Cars manufacturers could just implement the basics and let CarPlay/Auto do the rest but in that case anyone that doesn’t have a compatible phone is stuck without infotainment, same if you run out of battery.

CarPlay and Auto being so good is somewhat to blame for first party interfaces being that bad though: why spend litteral millions on look and feel if you know the users who care won’t be using it