Around here, you really cannot let your cats outside. There are too many predators - coyote, hawk, great horned owl, bobcat. It's dangerous. Sadly, we lost a cat many years ago, our adored Tweety. She got out one night, never to be seen again. :(
We have a neighbor that has cats. They live in their garage, and prowl the neighborhood. They keep them primarily to rid their property of rodents - pack rats and ground squirrels, that can tunnel and cause damage. People that find cats just drop them off at my neighbors. I cannot say that I agree with this philosophy. (These are the same neighbors who have no qualms about leaving their dogs outside barking either....)
One of their current cats is all black, and semi-feral (wild). When he was a few months younger, he took up residence in our garage for a while, and was very afraid of humans. Now he's older, and he's on the prowl. Because he is all black, he stands a good chance of surviving longer term. I hope he does. He's very cute! And still scared of me.