Average life expectancy is a midrange. Not an expected goal
It also can be misleading if you misunderstand what it means. For example a lot of folks think that people died a lot younger in the Middle Ages and Renaissance periods. In fact, people who survived to adulthood mostly lived about as long as we do now, maybe with just slightly shorter lifespans. The life expectancy was much lower then mainly because there were a lot more people then who did not survive infancy, which drags the average way down.