I wrote this in another comment earlier, but red meat is the most energy-efficient food source available for consumption in digestive terms, simply because our bodies were designed to process large amounts of protein rapidly - compared to plant matter that needs to be broken down multiple times. There's a reason herbivores have 4 stomachs. Human bodies basically evolved as Apex predators and a meat diet helped that, as well as was responsible for it. Meat, berries and tubers for hunter-gatherers to put it succinctly.

We only adopted carbs because back in the day, cereals were the most efficient way to feed a large population (compared to say large-scale veggie cultivation) for an active societal workforce. But with us slowly and inevitably turning into lumbering sedentary creatures, it makes no sense to continue eating as many carbs as we are culturally accustomed to, instead resorting to meats and veggies to adequately cover up that deficit. Unfortunately, you need a ton of veggies to make up that deficit, but you can make do with a much smaller sized portion of meat than you're usually accustomed to (as we see with East Asian diets).