Camber for drifting is to provide more or less grip or control. Especially on the front tires that lose contact surface when they are turned 80 degrees. Drift cars usually don't have much camber on the rear, the front is usually under 10 degrees with the top of the tire tilted inward.

Camber in the case of the OP has nothing to do with performance or practicality. It is done to be extreme, either in the case of camber for camber sake or to allow the car to ride as low as possible with the largest wheels/tires possible. The OP example is almost certainly camber for camber sake due to how extreme it is.