look at it another way. Why would a car manufacturer use a paint that is open to damage from plain detergent? It would take a lot of research to even find a paint that sensitive!
Of course, I’m a person that washes a car only when it gets really dirty (and hasn’t rained for weeks). Wax, what’s that? Why spend all that time and effort for no real result – at the end of 10 years will the car be worth any more?