Very little research currently goes into attacking aging directly - as opposed to handling things that are in no small part downstream from aging, such as heart disease. A big reason for poor "longevity gains" is lack of trying.
Sleeping well, eating well and exercising does work. Science about this is well-established. So why arent we?
It would not raise the life expectancy to 100 years but it would considerably reduce the health burden on the economy.
Those will give you at best another marginal decade. By all means worth doing but its not radical life extension. At the same time a young body can take lack of sleep and can physically perform even if not exercising much better than an old one. So there's more to it than just lifestyle.
Compare it to being obese, wich can happen very young and is in part determined by how you are fed when you are a baby/child.
Those will give you an entire life. Living while being healthy is an entirely different life than surviving while being unhealthy.