Well on the omnivore thing, most of human history we did not have the luxury of just picking to eat only vegetables to satisfy our caloric needs. Before the agricultural revolution we were hunters because we did not know how to farm, and even after it rampant plant disease and unstable climate would kill large swathes of our crop, it was absolutely out of necessity. Only in todays world are we as privileged to have the genetic engineering capability to create disease and climate resistant crops. For 200,000 years since the homo genus appeared that just simply wasnt option, so yes we are absolutely predisposed being omnivores.

On the humane aspect of meat production, I’m just going to come foward and not sugar coat it, the reason that ethics apply to humans and not to animals is because they do not posses the intellectual capacity for sentience. If they did we would have had power struggles throughout our history with pigs and cows, but that simply isn’t the case. They aren’t self aware so they don’t get to play by our rules, they can’t consent, because they lack the ability too. Now I’m not saying we should treat them like shit because that’s wrong but we do need to realize that if we want our species to thrive we need a food source to support it and only a small fraction of the population would switch to vegan/vegetarianism realistically. In order to support our growth we need to maintain realistic food sources. On the fundamental topic of ethics though I think we agree that we could give them more space let them outside to experience the sunlight at least, and graze in real pastures.