Cars spend a significant amount of time outside and they depreciate so quickly it just doesn't matter. One shouldn't expect a paint to stay perfect the same way we expect our skin to wear and age over the years.

I don't even know what a 5 stage detail means but I can safely say you are overreacting. A car is just a tool and a rando putting a fridge magnet or leaning against your car once in a while is just completely negligible compared to the amount of shit a paint is exposed to when driving it. Sand and dirt do not ask for your permission either.