In the 200,000 years since Homo Sapiens took her first steps across the African plains, just 57 billion people have ever lived. Astonishingly that means over 12% of all the people ever born are walking the planet at this very moment.
And 2/3’s of all people who have ever lived to the age 65 are alive today. Antibiotics, vaccines, and clean water— those solve almost all health problems that contribute to longevity and life expectancy. Once you save the kids, you spend trillions of dollars on medical care that pales in comparison to the effectiveness of those three simple interventions.