Mate Rimac from Rimac Automobili claims [0] that engineering a car is far more complex than engineering an aircraft, because:

1. the expectations the manufacturer places on the operators are wildly different (eg: car drivers won't deal with checklists, type ratings, etc.)

2. the expectations the operators have from the manufacturers are wildly different (eg: car drivers care about their UX and the perceived value, whereas pilots mostly care about their job security)

[0] In German: https://www.youtube.com/watch?v=PALxDIxRrns