Globally, for every 100 lbs. of human food that comes from crops, 37 lbs. of byproducts are generated. Much of that goes to livestock for feed. Some examples below of solar energy captured by plants that's unavailable to us without livestock upcycling it.
https://www.cast-science.org/wp-content/uploads/1999/07/CAST_R135_Animal-Agriculture-and-Global-Food-Supply.pdf
https://www.cast-science.org/wp-content/uploads/1999/07/CAST_R135_Animal-Agriculture-and-Global-Food-Supply.pdf