On a race car, some (not an absurd amount) of negative camber is needed because as the car leans into a corner, the outside tire gains camber. The car will have its best cornering performance when the outside tire is perfectly perpendicular to the road during a hard corner, because then the entire tire, not just the inside or outside edge, is gripping the road.

Here’s a good example of what this looks like in practice: this car has about 4° of negative camber on the front wheels in order to achieve 0° in a hard corner.