Empty… to humans but not to native species that living there. Grazing still affects those ecosystems there. From the article

As the cattle graze, they tend to disrupt ecosystems and do a lot of damage to the land. They eat or destroy plants consumed by native species, like turtles, which can lead to biodiversity loss. Their manure pollutes rivers and streams, and as they move about, they erode soil.

[…] analyzed decades of BLM data and found that about half of the acreage it oversees that has been assessed fails to meet the agency’s own land health standards (in Nevada, it’s an alarming 83 percent). PEER points to livestock grazing as the primary source of land degradation.

There’s an opportunity cost in using all that land. If we let land go back to its natural state we can sequester quite large amounts of carbon

A 2020 study published in the journal Nature Sustainability highlights the immense environmental potential of changing how we farm and eat. Researchers found that if all high-income countries shifted to a plant-based diet from 2015 to 2050, they’d free up enough land to sequester 32 gigatons of carbon dioxide — the equivalent of removing nine years of all those countries’ fossil fuel emissions from the atmosphere. Globally, if we shifted to plant-based diets over that same time period, the land saved could sequester the equivalent of 16 years of global fossil fuel emissions.