I often wonder about this too. Are we really living longer? Or is that a bit of a myth? My dad died at 64 of a heart attack, yet his dad lived to 77 and his grandad lived to nearly 90, so each generation died younger. I have been researching my family tree and was surprised to discover that some of my English and Scottish ancestors in the 1600s lived well into their 80s! Dr Johnson’s mother (1740s...ish) lived to 90 and Newton (1700s) was in his late 80s.
Of course, luck plays a part. But could it be to do with how we live as well? Most people eat so much sugar and junk. Plus the world is insanely overcrowded, which in turn means stress, pollution, etc. Then there is the all the garbage in our food and water - all the toxins, pesticides, plastics, chemicals.
Imagine someone born in the countryside in 1900. So long as they survived infancy, they had minimal stress, plenty of space and fresh air, and a diet that consisted mostly of locally grown veg (in fact, they often grew it themselves).
I agree that it’s terrifying. My local vet, who ran marathons, didn’t drink or smoke, and glowed with health, died of cancer last month aged just 52. No warning. He was diagnosed and then dead within weeks.