Some modern EVs already use drum brakes on the rear. Since they have regenerative breaking you don't get brake fade on long downhills. New EU regulations are c

Some modern EVs already use drum brakes on the rear. Since they have regenerative breaking you don't get brake fade on long downhills. New EU regulations are coming in to limit brake dust and so people are looking at them again. And other ideas, like mercedes has a prototype that puts the brake inside the motor.