A dozen years ago, backup cameras were $$$. Today, all the parts are less than $20. Cost is no longer a factor. It is simply wise to have the technology available.
I recall when you could buy a car with or without power steering and power brakes. I still think that you can drive without power steering. You can stop without ABS. People slowed down to a safe speed without traction control.
Today, every car comes with a camera. You can't fight progress.
May as well argue that the square wheel was a better design.