when the organism has done all the breeding they're going to do
You could argue that having older and more experienced individuals around might increase chances for survival for everyone. You'd predict that that effect would be especially pronounced in a species that highly relies on culture, like us humans. Indeed the hypothesis was found true for orcas: https://www.pnas.org/content/early/2019/12/03/1903844116
It can be true, but for a gene to reach fixation, it has to be selected for, i.e. organisms without it have to die before breeding.
So this effect might work out if you have a lot of isolated sub-populations, and the ones that live less long suffer extinction, while the ones that live longer go on to eventually reconnect and breed. But it doesn’t really work in a “liquid market”, because free riders without the longevity genes will be just as successful at breeding (due to the existence of the long-lived species members) as the ones with those genes.
You could argue that having older and more experienced individuals around might increase chances for survival for everyone. You'd predict that that effect would be especially pronounced in a species that highly relies on culture, like us humans. Indeed the hypothesis was found true for orcas: https://www.pnas.org/content/early/2019/12/03/1903844116