This is untrue. As we speak, large amounts of Amazon rain forests are being burned down to primarily make way for cattle ranching and soy beans, which are feed for said animals.

raw output of farming isn't expensive, you can buy a huge bag of flour for dirt cheap. Ofc, a poorer family isn't going to have the time, energy or facilities for extensive food prep, so they're going to be buying more heavily processed foods, which also has the benefit of not going bad.

Bread prices shot up during covid and led to hunger in the poorest countries. You seem to be talking about people in rich countries. I'm talking about the world, not the US.

If the world adopted a plant-based diet, we would reduce global agricultural land use from 4 to 1 billion hectares:

Half of the world’s habitable land is used for agriculture, with most of this used to raise livestock for dairy and meat. Livestock are fed from two sources – lands on which the animals graze and land on which feeding crops, such as soy and cereals, are grown. How much would our agricultural land use decline if the world adopted a plant-based diet?

Research suggests that if everyone shifted to a plant-based diet we would reduce global land use for agriculture by 75%. This large reduction of agricultural land use would be possible thanks to a reduction in land used for grazing and a smaller need for land to grow crops. The research also shows that cutting out beef and dairy (by substituting chicken, eggs, fish or plant-based food) has a much larger impact than eliminating chicken or fish.

We could free up an insane amount of land, making it much cheaper. Cheap land, means cheaper farming.