DH you're a dimwit and no one on nubblies cares what you have to say about these topics, thankfully you're a joke around here and not a serious harm.
Some things that were adaptive on the ancestral landscape are currently maladaptive, just because humans have done something for thousands of years doesn't mean it's a good thing or pinnacle of nature.
Why do vegetarians tend to live longer than meat-eaters?
The intelligence and longevity gap between vegetarians and meat eaters would probably be greater with creatine supplementation.
Creatine in mouse models of neurodegeneration and aging. - PubMed - NCBI
Creatine in mouse models of neurodegeneration and aging.
The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores. - PubMed - NCBI
The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores.
National Child Development Study here in the UK, vegetarians record a mean childhood IQ of 109.1. Meat eaters record a mean childhood IQ of 100.9.
the intelligence gap is both large and statistically significant.
Childhood intelligence and being a vegetarian
"I think the 8+ point IQ gap here in the UK between vegetarians and meat-eaters unduly flatters meat eaters. This is because today's so-called IQ tests are "mind blind". Any test of general intelligence with ecological validity would give due weight to scoring the mind-reading prowess that drove the evolution of distinctively human intelligence. Such a test would almost certainly show the disparity in intelligence between meat-eating dullards and vegetarians is higher still."
Why Do Vegetarians Live Longer?
"Why Do Vegetarians Live Longer?"