What we view as attractive is socially constructed and varies over time and place. See e.g. https://www.sciencedirect.com/science/article/abs/pii/S0738081X23000251

Youth and health are probably a proxy for fertility, so that would be related to physical attraction, but why should that affect how we treat people? That's not a reason to favor the young or to disfavor the old. Not only that, but community care of children meant everyone had a role in the greater sense of "fertility".