Yes, often the maps are bad, out of date, and require one to go the dealer and pay money to get an update. However, once out of the city, and cellular data ceases to be a thing, Google maps and similar applications built with an assumption of an always-available Internet connection become kind of useless. Yes, you can add maps for the areas you are planning to be to your offline areas, but that requires planning ahead. And if you ended up somewhere you didn't plan to be, well, good luck.
The UI for these in-car navigation systems is bad, but at least you have _a map_, instead of a featureless void with a blue You Are Here in the middle. Personally, I like a map book for such situations. Sure, it's ancient and obsolete technology, is quickly out of date, but the UI is quick an easy to learn, and it doesn't require power to use.