You also forgot that they are fast with responsive UI. And that's only if you compare the best of the car built-in GPS. If it is not the top of range (which btw is not related to the price of the car), the UI is generally awful.
If you are a google/apple map user. Searching for an address is a million type easier: roughly type some part of the address and it will find it. No such luck with car gps.
At this stage you wonder why car manufacturer even bother. They should just allow to plug a tablet and run software made by people that understand software, and restrict themselves to providing a simple interface to car metric, hud and maybe cameras.