One soybean produces three times the waste is oil cake as it does edible food for humans. That leftover oil cake is fed to livestock. More soy production and no livestock to consume the waste and convert it to calories, significantly more waste and nothing to do with it.

There is not a single farm that produces feed for livestock. Livestock eats the crops not suitable for human consumption — so do your pets, that’s what your pet’s food is made from, the same leftover waste. Take away the livestock that converts waste into calories, now what? What happens when you have to significantly increase crop production and now have significantly more waste and nothing to eat it?

Besides the fact that land used for grazing (because cows predominantly eat grass, not feed) is not suitable for growing crops, which is why it’s used for grazing livestock in the first place. So you go away with grazing livestock, you have a bunch of empty land that can’t be used. But let’s say we come up with a way to magically make it usable: land used to grow crops has to be completely cleared and devoid of any other life, including animals and insects that eat the crops. Grazing land also grows local flora, trees, and is home to thousands of local fauna — rabbits, deer, mice, armadillos, and so many other animals and insects who live in and rely on that grazing land. So now you’ve just displaced 10 times the amount of wild animals to grow crops instead of raising cattle.

That’s neither better for the environment nor less cruel to animals. That’s even more cruel to animals and worse for the environment solely so you can have soy milk.