Correction: Close to all animals that end up becoming our dinner live horrible lives way below the minimal standards set by even the most conservative animal rights organization. Full lives spent in tiny booths that barely fit the animal, placed on top of a hard concrete floor and without ever experiencing sunlight is the complete and full summary of millions of livestock animals' lives. The more "humane" way of raising livestock that you describe is reserved for only a tiny selection of animals, and is often the case for animals ending up on the plate in Michelin restaurants and the like.
Also, it is not a question of either spending life in the wild or in a farm for these animals. Domesticated pigs or cows or chicken wouldn't be in the wild if they weren't being prepared for slaughter, they simply would never have been born in the first place. Nevertheless, to humor your point: getting attacked and eaten in the wild means exactly the same result as with livestock, with the exception of the animal living a life prior to its death in accordance with their needs, with free mobility and with freedom to pursue their instincts.