Veganism is only a thing because of modern medicine, supplementation and technology. Without B12 shots, bloodwork and specific supplements that supplement what is a malnutritious diet, veganism would not thrive. 100 years+ ago, what you do today was not possible to be healthy, hence not evolutionarily consistent. That said, if you were carnivore 100 years ago, you would be just fine. If we didn’t have the ability to analyze even the basic proteins in our foods, the protein shakes you take would not have complete proteins.