Over the last 20 years, we have adopted 3 cats from a feral cat community that used to thrive in the creek behind us. The community is gone now, not by predators, cat ladies captured and sterilized the cats until the community died off.
Cats get extremely tough, the ones we adopted became family pets, that lived full lives as outdoor cats. Coyotes, raccoons, owls, and hawks feed in our yard on a daily basis, if the cats were patrolling the predators would run -- they seem to know messing with cats doesn't always end well.
Same with my BIL's barns (he has 4 on his farm). Their cats come and go with food supply, when there isn't enough food the cats leave for another barn. He doesn't have predators taking them.