I think the future of age-related research is going to focus on inflammation. There is already a term for it: Inflamm-aging[0].
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850851/
As it points out, the most obvious and promising of current prospects for reducing inflammation is the selective destruction of senescent cells. Though I think that the clearance and recreation of the entire immune system, to remove all of the senescent, exhausted, misconfigured, etc, immune cells is also a promising path, albeit further away from being safe enough to apply to old people.