The sensors are nice, but sensors+camera improve on that by an order of magnitude - you do not see behind your car, no matter how much you think you do. Especially small people aka children are completely hidden from the driver's point of view by the rear of the car - which is exactly in the camera's center of field.
I got a shocking example of this recently. I was towing a trailer behind my vehicle for a 14' boat (the trailer was quite a bit longer than that). I was really surprised that I could not see it AT ALL in my rear view mirror when the boat was not on it. Meaning there is at least 16' behind my vehicle where I cannot see something about 2' tall or shorter.
