AFAIK this statistic is often misrepresented; the average life expectancy was lower, but largely due to infant and child mortality. Once you made it past 12 or so, you could reasonably expect to live a similar length of time as people in the modern era.

However, your point is still valid in a way. Life back then was physically harder and the state of healthcare was obviously nowhere near what it is now. People likely showed their age much more quickly than people today.