as the game features nobles and other big-shots, many of the life-shortening threats facing the general population don't apply. Nobles mostly don't have to worry about starving to death, being killed in the street, freezing in winter, fighting in battles without training or equipment, or having body parts removed for petty crimes.
If someone can survive childbirth and childhood disease, keep food and shelter, and be lucky enough to not catch the plague or get murdered, they could expect to live a long time.
It's nice to know childhood survival hasnt changed much.