Oh, yes, lol. That makes sense. But they're still vulnerable to injury and disease... and, unfortunately, probably killing a lot of birds and lizards that will struggle with the evolutionary pressure.

But you're probably relying on them for rodent control, right? As a rule, I think all cats should be indoors, but this is a case where it's not so bad if some people get exceptions. Presumably there's plenty of wildlife habitat where small critters can escape your cats without getting in your house!