I agree. For eons, humans have eaten plants, 100g fiber per day and lots of starchy roots. That's when things were good, we starved otherwise. Meat was a delicacy and only a recent phenomenon as is drinking milk.
Look at central African countries and how they eat, mostly starchy foods and rice, very little to no meat, virtually no colon cancer or diabetes. Women will have 10 babies and live to old age if not for other factors, also no osteoporosis.
"However, there are several possible reasons: Red and processed meat contain haem iron, which makes meat red in colour. When haem is broken down in the gut it forms N-nitroso compounds. These can damage the cells lining the bowel, which can lead to cancer."
Anyway, I eat much less meat now, not for animal cruelty or environmental reasons, just anti-cancer reasons. So yeah, bean based diet will keep you going. Also the Irish ate nothing but potatoes for generations, look how they turned out......