To be clear I'm not saying: don't eat meat.
What I'm saying is you don't need to eat it 2-3 times per day. I don't eat meat by choice.
> Historically humans depended on animal protein for essential amino acids. It seems far-fetched to suggest we could scale up quinoa to 7+ billion humans given current global realities.
I'm curious how you think we're feeding those 7+ billion today? If you're saying that animal production globally is efficient with respect to natural resources and waste, well that's even crazier than growing plants via alternative farming methods.
> Humans naturally consume animal protein out of biological necessity.
This is where the argument is lost on me. I'm not sure what point is being made here but it reads as if you're saying prehistoric humans got their protein through animals and animals only. This just isn't true and some research has stated only 40-50% of protein was acquired via animals. But the real problem here is that sales and marketing has led us to believe that we need more protein. Way more than we actually need. So much so that we're polluting via urine because of overconsumption of protein [0].
[0] https://www.scientificamerican.com/article/eating-too-much-p...