Ruminants are much more efficient processors of plant fiber than humans are. They also eat a lot of agricultural waste that humans can’t.
To replace the calories lost from meat, we’d actually need *more."
Not to mention that we’d be creating a lot of agricultural waste we can no longer deal with.
No offense if you’re on a vegan diet, but vegan diets are ridiculous. They aren’t the solution they’re purported to be, and most people can’t stay on them longer than a few years before health issues creep in.
Not to mention the swathes of the population that are diabetic or prone to diabetes that require a low carb, high fat diet that can’t be easily done vegan, and can’t be done in a healthy way without animal fat and protein. Not without a lot more nuts and avocados which are, as it happens, huge problems for the environment on their own.