There have been two sides to this issue, and you may have missed the nuances involved. First, you have the voice recognition/internal systems that many auto makers have. Then you have Android Auto/Apple Car Play support. In some cases, if the car includes its own voice recognition system, that tends to mess up integration with Android/Apple voice support, because the voice button goes to the system the auto maker has included, and in many cases, without there being an option to set which one you want the voice button to work with.
Now, Google has been adding new features into Android Auto, such as climate control support. Obviously, the car maker needs to enable that functionality, but for new cars, you SHOULD be able to hit the voice button and tell it to set the temperature to whatever, turn on/off the front/rear defroster, and things of that nature without needing to hit any buttons. A number of auto makers have skipped on trying to reinvent the wheel and don't even have their own voice control system, the button goes to Android/Apple automatically and uses the assistant on your phone.
There are relatively few people who would benefit from internal navigation, such as those who live in extremely rural areas that don't have cell phone service EVERYWHERE, but the idea of the auto maker making specific deals with Apple or Google seems like a complete waste of money.