Homo sapiens are arguably the most adaptable species on the planet, a strength from advanced cognition and biology. We're defiant of core physiological and environmental processes to favour our own evolution and survivalism. In respect to diet, most people can comfortably consume and benefit from animal products on a nutritional level.
Need/natural is such a whimsical argument though, because we by nature make decisions and drastic lifestyle changes that are at odds with conventional naturalism. It's why despite making the choice to go vegetarian (inevitably vegan, but give me time) the arguments against animal products as "unnatural" are generally based in poor science. I don't buy them, as it implies my choice to not eat meat is somehow aligned with a biologically natural state that all of human society over centuries is conveniently in opposition with.
Ultimately, at least for me, it's a logical, ethical driven choice. I love the taste and complexities of meat, I can benefit nutritionally from meat, I enjoy the process of cooking meat, but I don't need meat. In order for me to eat meat, unless I choose to hunt my own game, I must concede to supporting the industrialization of animal slaughter. I oppose the objectively negative environmental impact of industrialisation, and ethically I oppose the objectively unnecessary suffering of a living creature in modern Western society. I don't feel any sense of superiority of betterness from the choice; I don't feel there are objective moral guidelines innate to complex beings like humans, and so if someone legitimately feels that animals exist to serve us as a source of food then even if I disagree that's just a point of contention. I'm also well aware of the complexity of society, industrialization, and simply existing in that hypocrisy is guaranteed as I am likely in some way, if abstractly, contributing to suffering (especially since I'm vego, not vegan yet), so I have no delusions there. But knowing that I can comfortably, affordably live my entire life with perfect health and nutritional benefit without a living creature suffering through choice, and that consuming meat/animal products is 100% a conscious decision, encourages me to cease supporting that which I morally/ethically oppose.
Thank you for reading my pointless train of consciousness that nobody asked for. Back to shitposting in Mass Effect threads.