I think the biggest loss is that we forget that killing domesticated animals for meat is actually more humane that letting them "live their best lives" or whatever. PETA would not exist in a more agrarian society.
Cows, chickens, pigs, and the like have been shaped by human breeding to the point of interdependence, just like dogs. They are made to serve our needs, and the animals live their most proper, happiest lives when they are cared for, allowed to eat, play, and reproduce, and are given a swift death as painless as possible.