Although this is true, I wonder how different those requirements could be.

I could imagine that, like with many other things in nature, these requirements would follow a somewhat bell-shaped curve, with some people doing better with more or less meat, or respectively plants.

But, in the end, as humans we get complete proteins from fish, eggs, meat, and dairy, and incomplete ones from plants, nuts, and seeds, and natural selection would dictate that the former sources are the preferable ones in general (not to mention that they also come with much more bio-available nutrients, like, I don't know, B12, K2, zinc, iron, calcium, taurine, creatine, ...).

I don't know if it is even debatable in science, but I think that humans are omnivores, yet more animal-based. It is for sure an evolutionary advantage to be able to process plant-based foods, but they are not really essential.