Caveat: I'm a huge meat eater. Love the stuff. Can't stop won't stop.
BUUUTTTT the natural fallacy has to die. Just because we did something for the last N millennia doesn't make it worthy of continuation.
Just in case. Many people think that a fallacy existing is proof of the contrary position, or at least they speak/argue/type as if that is the case.
The corollary of course is that despite the apparent fallacious reasoning you could be right.
And my point wasn't that we should do something just because it's been done before. My point is that if veganism was "natural and optimal", then why hasn't any human society in history adopted it? Because humans cannot survive on a vegan diet without supplements.
In other words, my point is that if the vegan assertion that "veganism is the optimal natural human diet" ( aka what humans were meant to eat ), why has no human society ever adopted it and why can't humans survive on a vegan diet in nature.
I don't know if that's true. We may not have been able to supply the amount of vegetation required to keep a human being upright and functional a millennia ago, but now that we live in the age of abundance, with food diversity that's unprecedented that may not be an issue at all. We can artificially create a complete diet of strictly plant matter with intelligent choices.
That's very hard to distinguish from supplements. Some nutrients are hard to find in useful quantities in plants, so you need a ton of them. The most practical approach is to extract and put them in a pill. Supplements. Nothing wrong with it.
I think when somebody asserts x is the best diet because x is what we have been doing for thousands of years, x most often includes eating meat. There is a whole diet based around this idea called the Paleo diet. It may very well be the most popular diet of the last 5 years.
The only time I can recall it being asserted that veganism was the historic human diet, it was by a total quack YouTube personality. Veganism was also tangential to this claim; the claim was that the diet should be 100% figs.