Without medical intervention over 50 we all likely would be dead

This is why even in 1900 people tended to die around 60 on average (if they lived to be 20 to begin with) because most people died then before 20. This doesn't mean that Some people didn't live to be 80, 90 or 100 either because I met many people this old in the early 1950s who had lived through the Civil War or rode across the U.S. in a covered Wagon or Stagecoach or rode one of the first trains from Chicago to San Francisco over the Rockies and Sierras. (When I took the Zephyr train from near Berkeley to Denver a few years ago it was an amazing experience by the way. We rented the largest private room which has it's own shower and sink and toilet and usually two beds and a window to watch the scenery go by day and night. One of the most amazing things is a tunnel it takes at least 10 minutes to go through and if any hobos are on the outside of the train  and don't know about this they die in that tunnel all times of year because the air isn't breathable and survivable in the tunnel at all ever. The tunnel goes directly under the highest points of the Rockies and starts just after you leave Winter Park, Colorado going east.

So, the other day I realized that without a doctor and medical intervention in my life I would already be dead at 70. This is likely true of most people on earth by the way, (I'm no exception to this rule). I first had to face this when I had my burst appendix and needed an operation 1 week later to stay alive (then in 2015).

It totally destroyed my belief system as to what I could and couldn't survive. Suffice it to say with present medical technology you can now survive things you wouldn't believe in your present belief systems worldwide.