OTOH, you'd accumulate uncurable disease, injuries, etc as well. Maybe you become a disease resevoir inside your own growing family. Or you pass on as-yet-unknown genetic anomalies that are unhelpful, and you do so forever.
Granted that's a modern take, and in particular a modern rpg-like take. Regardless though getting rid of oldies seems like a reasonable way to move a species forward if natural selection is driving "forward".