I see you understood my point. Things change. The only thing that remains the same, is change.
God made the universe so life could evolve.
Yes, but those figures are down from the averages of the Revolutionary War and basically reflect harsh conditions during the westward expansion that preceded the Civil War. Remember the name of Roy Rogers's backup singers? "The Sons of the Pioneers." The real sons of the pioneers grew up scrawny on hardscrabble pioneer farms and then had to fight the Civil War.
There was a high reject rate and a high mortality rate from exposure, TB, and pneumonia during hard-weather campaigns like Fredericksburg in late 1862. Poorly-supplied Southern soldiers in addition faced the menace of scurvy at times.
Here you have point, and you don't. Average life expectancy has risen dramatically in developed countries. That reflects good eating and good health care.
Maximum life expectancy has only slightly budged as modern technology attacks late-life killer diseases such as stroke, heart disease, and cancer. There have always been a very few people who lived to be close to 100, even in pre-tech societies in hard conditions. In the NY State/Great Lakes region of the late 1600s, Daniel Garacontie in his 90s was an important chief of--I think--the Iroquois. The average life expectancy for that time and place would have been laughably low compared to what it is for the modern residents.