Not sure -- in some cases they could help. Lots of cars today have body styles that restrict vision to the rear. I'm leasing a Chebby cruz -- and it's an issue.
OTOH, I imagine that they get crudded up pretty easily.

hj

 

Ford has had camera washers for a while.

 

I have two passenger vehicle with the rear camera's and I've found that the sensors do a better
job with alerts as I'm still in the habit of looking back.

 

Dinosaurs are history. Model T's are mostly in museums. Technology marches on. Vehicles are marvels of technology. You haven't seen the half of it. 5G is coming, like it or not. And this only the beginning of what is in store for us. I regularly attend CES (Consumer Electronic Show) where all the latest trends (and flops) are marketed. I have seen the RV;s, trucks, and cars in our future. In many there is not a piston to be seen, nor a steering wheel. I too am not fully comfortable with this, but the economic pressures that are "driving" this are practically irresistible. The truckers, early adapters, and seniors will be first, and slowly (or quickly) the rest of us will be crowded on to the transportation arteries in the not so distant future.
regards
Bill