It is not easy today to reproduce 1960s snake-eater physiognomy. It is a strenuous, lithe, leathery physique, hardened and not bloated.
Not impossible to reproduce, but difficult. Everything today is so different: food, water, culture, ethics.
Storming an Austin tower in 1966 with only .38 revolvers and an on-the-spot-deputized citizen with a hunting rifle, to confront an active shooter.
vs.
Hiding behind bushes in 2022 like a chickenshit while kids get killed, waiting for the "tactical team."
Huge difference.