Once again, you are trying to compare units which are not fungible.
There is more land on which you can make meat than land on which you can make plants. Animals can graze on non-arable scrubland, grassland, etc.
Growing staple crops is harder on the land than raising animals. Staple crops deplete soil nitrogen and other nutrients.
Raising crops typically requires massive importation of fertilizer from petrochemical plants, whereas cattle grazing (for example) does not require significant additional petrochemical input.
A classic tale of how animals unfairly take the heat for plants: we often hear about how the amazon is being cut down "for cattle". If you actually look into it, what's happening is that farmers are cutting down the amazon to grow soy for around 3 years, until the soil is totally depleted, at which point they will put some cattle on the land because the cattle can extract value from land destroyed by soy and helps the farmers maintain land claims.
We raise very few animals purely through grazing on non-arable land. If nothing else, they need feeding through part of the year in many climates, and more typically, supplementary feed to increase intensity. Pure free range non-arable grazing ruminants constitute a relatively low percentage of total meat produced.
A somewhat more common thing is to raise cattle on arable fallow land between crop cycles. This is better than keeping permanent pastures, but nowadays we still often supplement the feed or intensively finish.
Battery farms, which is purely fed on crops grown where humans could grow food, accounts for about 70% of beef and 99% of pork and chicken. Often the soy being grown in the rainforest is to support these animals.
The other thing is a lot of "non-arable" and fallow land is actually a lot more arable with modern agriculture than it used to be, it's just more profitable to grow animals. A lot of the plant matter that used to be considered as only usable for animal feed can also now be processed for further use in human food.
Meat production isn't quite as bad as people sometimes suggest, but it's still pretty bad. There are some cases where it is still a good option (e.g. low intensity lamb grazing on rocky/hilly terrain) and if we scaled our meat production to only these cases, we'd be in a much better situation, but there's also be way less meat.
> Battery farms, which is purely fed on crops grown where humans could grow food
They are mostly fed on the byproducts of human food production. Human-edible material has higher margins than cattle feed, so cattle feed either comes from human ag byproducts (like soy meal) or from land that probably isn't good for much except hay.
There is more land on which you can make meat than land on which you can make plants. Animals can graze on non-arable scrubland, grassland, etc.
Growing staple crops is harder on the land than raising animals. Staple crops deplete soil nitrogen and other nutrients.
Raising crops typically requires massive importation of fertilizer from petrochemical plants, whereas cattle grazing (for example) does not require significant additional petrochemical input.
A classic tale of how animals unfairly take the heat for plants: we often hear about how the amazon is being cut down "for cattle". If you actually look into it, what's happening is that farmers are cutting down the amazon to grow soy for around 3 years, until the soil is totally depleted, at which point they will put some cattle on the land because the cattle can extract value from land destroyed by soy and helps the farmers maintain land claims.