Humans’ greatest anatomical advantages paved the way for the growth of our frontal cortex and higher intellect. Our mandible thumbs allowed us to grip and design tools and weapons. Moving away from the trees and standing up accelerated us ahead of our nearest primate rivals. We developed glute muscles for running, jumping, throwing.

Our shoulder capsules allowed for 360 degrees of angle - more than any other species on the planet. This gave us more capacity to adapt to our environment with greater efficacy and design more complex weapons like spears. It also meant we could engineer things with ropes and sails and oars while using the strength of other animals to create agriculture.
Fast-forward to the industrial age and we see a modern version of humans that still had an environment that required higher levels of physical activity. By default their lifestyle required it. Food was nowhere near as abundant or calorie dense and much more nutrient dense. The social and industrial construct required more collaboration and better personal communication because technology hadn’t removed our capacity to connect with our fellow human.
The turn of the century saw the introduction of automation and the rise of machines and technology. For the first time in our history, we can no longer rely on environmental and physical adaptation the cornerstones of human development to help keep our bodies supple and resilient.