I think our feet are as sensitive as we allow them to become.
I grew up in southern california. In summertime my brothers and I rarely wore shoes, and a little more frequently wore flip flops, but usually our feet were bare.
One brother and I use to run - just for running - on our neighborhood streets, barefoot, on asphault (the only sneekers I owned were saved for PE class at school or for Little League.
Our feet were so black my mom made us wear socks to bed.
It was a very long time into adulthood before walking on any surface registered a complaint from my feet.
I think our feet are only as much in need of shoes as we have trained them to be.
It helps to be as light as a child. Much easier to walk on rough surfaces when you weigh 60 lbs.