They don’t have to be feral. Friend’s of our raise pigs and when the husband is out in their pens, his wife watches from the kitchen with a loaded shotgun.
You are right. Your friend and his wife are smart to do that.
Wild boar’s and sows here can get pretty large, some way over 400 lbs. But domesticated hogs tend to get even larger, because of breeding and diet. All of them can hurt you.
As can cows, bulls, horses and many other farm animals.
The anti-firearms wackos in the cities have no idea how dangerous wild animals can be. When I was growing up, most pickups had gun rack in back window and a shotgun and a rifle was always in the rack. No one ever had one stolen. Not so now. Many still carry a rifle in the tractor or the combine (in season) to kill coyotes and hogs. (wild hogs here are a plague, so many of them)