If you're coming from europe, i can understand how it's hard to wrap your head around the type of land in the western US, because there's isn't really the same type of thing anywhere in Europe to my knowledge.

Just the Bureau of Land Management handles around the area of one tenth of all of Europe (around 1 million km²). That's public land, no one lives on it. Almost all of it is used as grazing land to some extent. It's not really used otherwise except for recreation. That doesn't include national parks and national forests which are also commonly grazed in part. It doesn't include huge ranches that aren't factory farms. It doesn't include small farms and landowners that rent out fallow fields to cattle ranchers.

And the yield of that land is extremely variable. My 3.4 acres are listed among the highest potential yield crop land I've seen at well over 100 bushels per acre of most common crops. 10 miles north of me there's rolling hills of pasture land that probably could yield 25-40 bushels per acre if you could farm it. 100 miles southwest of me, your crops are probably just going to fail, but cows can scratch together enough food to gain weight for 11 months of the year.

So, factory farms put feed lots on land like that to the southwest of me and then buy feed from my neighbors here in the extremely fertile area. They can actually have 100 cows per acre. The ranchers to the north of me are probably running 1 cow per acre. Any ranchers to the southwest doing grazing are probably more like 5 acres per cow.

The factory farm needs crop land, and i can't find the actual calories per acre for just grass hay, but wheat is significantly more calorically dense and that's around 6.4 million Calories per acre. Corn is 12+ million, and that's for human consumption, but cows eat the stalks, too. So, i think a reasonable estimate would say a feed crop produces perhaps 3x the calories per acre of grassland on the low end and upwards of 10x at the top end.

So, ranching cows on pretty decent grassland is 1 acre per cow. Factory farming requires 0.11-0.31 acres per cow (0.1-0.3 acres for feed, 0.01 acres for pen space, plus a tiny bit for waste control). And the worse the land yield is the more acres you need. Factory farms exist for a reason: they're cheap and efficient.

But ALL that land is weighted the same in your narrative. It isn't the same at all. Factory farms and cropland is essentially worthless to wild animals. Rangeland is some animals primary habitat.

Monoculture crops can actually be much more damaging to the environment than rangeland raised meat, even when you account for the area required per calorie.