While animals can eat waste from crops grown for humans, that’s a minority of their feed. Almost all new corn and soy cropland is cut to meet growing animal agriculture demand.
How does eliminating animal fat and protein cause health and nutrition problems? Humans are perfectly capable of living on vegan diets at all stages of life.
Companies and their leaders are paid by individuals, lol. Going vegan definitely does help.
Even still, why did you only mention carbon emissions? The question was about making a better society. Did you forget that veganism is about animal rights?