“When we realized that elephants provide extraordinary fat deposits for humans, we realized that fat provides double the energy of meat without any digestion cost,”
So the true “paleo” diet is not lots of lean protein, but lots and lots of fat!
For the majority of human history most of mankind’s efforts have been to produce enough food to survive. Many people existed just barely above starvation level.
It wasn’t until the late nineteenth century that agriculture started to get more efficient. Farmers could produce more food per acre. The twentieth century saw even bigger gains.
In 1900 about 97% of all jobs involved the growing, transportation, and distribution of food. In 2000 only 3% of jobs involved food. That freed up people to develop new technologies instead of trying to feed themselves.