We were already using Apple Maps pre-iOS15 because its turn-by-turn directions were far superior.
With Google Maps, we were often surprised by the directions: it would be like keep left... keep left...TURN AROUND NOW.
Apple Maps often shows the next two directions, and more clearly dictates what we should do next.
... with iOS15, Apple maps are just gorgeous, and I've completely deleted Google maps (I now have no dependence on Google services for personal life).
Google has sat on its hands the last couple years with Google Maps: it has hardly improved at all, and outside of their move to jack up prices for API users, I haven't heard of any real changes.