I think this is a great example of "what's good for the individual, is bad for humanity as a whole". Imagine we'd discovered a drug that adds 100 years to a persons natural life. Now imagine this drug was discovered 100 years ago. J.D. Rockefeller and the likes would still be alive and influencing politics. I can't even begin to think how much humanity would stagnate after such an invention.
See also the Planck principle: "A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die and a new generation grows up that is familiar with it"
People don't need life-extending drugs to hold onto power or ways of doing things, that's what dynasties are for. And if in a democracy somebody like J.D. Rockefeller gets a voice that is too loud, then the democracy is flawed and we the citizens are ultimately at fault.
See also the Planck principle: "A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die and a new generation grows up that is familiar with it"
https://en.wikipedia.org/wiki/Planck%27s_principle