> most of the land that livestock use for grazing is unsuitable for conventional farming anyway

Ah, but are most cows in the world actually grazing on pasture unsuitable for arable farming? I wasn't able to find an estimate of that number, but am willing to bet good money it's pretty low, considering that the number one driver of tropical deforestation is converting land to raise cattle, and the number two driver is soybean production mostly to feed said cattle: https://www.worldwildlife.org/magazine/issues/summer-2018/ar...