Comment by observationist

Heritability acts on lineages, not individuals (in general, not always) - a good rule of thumb is that traits that benefit 3 or more generations of a family have a good shot at being propagated. In this case, the advantage (of both menopause and longevity) is increased well-being of the tribe, ampliyfing the positive effects of culture and stability. Wisdom of the elders is implicit to the genetics. This is a tradeoff with the cost in resources; at some point the cost to keep someone around might exceed the benefit, but from an evolutionary standpoint, the accounting is over a lifetime; in a relatively stable environment, genes that improve longevity and healthspan will be reinforced by the positive feedback loops of culture and nurture and civilization and technology. Menopause is also prevalent in orcas and a handful of other mammals - and older females help rearing and protecting babies, and so forth, with a protoculture providing that feedback loop.