Not all land is suitable for crop cultivation, which was the point I was making. In subsistence or low tech farming areas, animals forage on land unsuitable for crop production and eat food unsuitable for human consumption. They’re not eating feed, they’re eating wild weeds and grass we can’t. They’re eating insects, miscellaneous seeds, small plants and whatever they find.

Do you think that if you’re farming to have enough food to feed your family and maybe some leftovers to sell, that you’re going to choose to produce something markedly inefficient in comparison to other options?
Subsistence farmers today aren’t stupid. They’re not wasting 90% of their food because they want a hamburger. They raise goats and chickens because they feed themselves and you let your kid who’s too young to do heavy work follow them with a stick to keep them from wandering off. They raise cattle and donkeys because they can forage, and what they can’t forage is more than made up for by using them to work the land or as beasts of burden.

There’s a reason we domesticated animals. We didn’t just immediately start giving them feed corn and locking them in cages.

It’s a privilege to be able to ignore a readily available source of food.
It’s a privilege to live in a society where we set aside land to grow huge amounts of food to feed our food.
It’s a privilege to not have to know specifically where your food is coming from.

It’s kind of ignorant to think that people who don’t have those privileges must be foolish enough to choose what you think is an inefficient option, and to not consider why they would make that choice.