I agree on indexing retirement age to lifespan, but I doubt that would get much support. See ex. the protests in France. In the U.S., the elderly are a very powerful voting bloc.

I'd argue another concern could be useless/harmful interventions. Like taxpayers paying 82k a year per person for Leqembi treatments, which seems useless at best. There are also a lot of interventions that drag on terrible-quality lives in an attempt to forestall death as long as possible; I have personal experience with elderly family members who expressed a preference for death over their treatment plans (but were no longer able to choose). If I retain the ability to choose, I would go to great lengths to avoid some of modern medicine's pallative care.

I don't know. It's all hard. Obviously I want elderly people to be healthy and cared for as much as possible, but not at infinite cost (to the taxpayer or to their own quality of life).