Locking out phones would be a big liability. Accidents, attempted car jacks and such... Perhaps if only 911 was permitted.
I don't know how we survived without cellphones...
I had my first back in the '80's, and had to limo tint my windows to keep people from stopping in the middle of intersections and pointing at me while I was on phone waiting for the light to change. Not many mobile phones back then as I had more $6000 a month phone bills than I care to remember.
It is all about personal responsibility...