During the Victorian era, children commonly died of illnesses like measles, mumps, and whooping cough; surely, no one would suggest today that we eliminate prenatal care, vaccines, or water purification in order to return to a more "natural" state. Now that we have the technology to eliminate the scourge of infant mortality, it would be immoral to not use it. In truth, we’re fighting aging and extending lifespan every time a doctor prescribes a statin drug or recommends a healthier diet to a patient. And the fact remains that science has not yet discovered an indisputable biological "expiration date" for a human life, nor is there good evidence that one exists.
In time, the idea of an inevitable, debilitating decline starting at age 50 will seem as horrifying and primitive as it does for us, in the age of potent antibiotic cocktails, to imagine a young person in the 19th century dying from an infection caused by a splinter. As a society, we should not accept a terrible period of suffering, dependence, sickness, and frailty if we don’t have to. There’s nothing more natural than marshalling the body’s own defenses to treat and heal itself, and that is precisely what longevity genes like SIRT1 do.
As I'm sure you're aware, I think that there are compelling arguments to say that chasing metabolic alterations as a path to any significant extension of life is a pipe dream. It will be enormously expensive and most likely produce therapies over the next couple of decades that slow aging to much the same degree as the simple practice of calorie restriction. Which does little for those people who are already old - such as we folk reading this now, getting older as we wait.
Meanwhile, there exist strategies that could produce technologies to reverse the damage of aging in the same period of time, at a similar or lower cost. This is, unfortunately, the minority view at present in the scientific community.
I have discussed these two paths before, and I consider the mostly obscure debate within the scientific community over research strategies for engineered longevity to be very important. The end result - meaning how long it will take to ramp up a research community eager to repair and reverse aging - will determine how long we all live. It is, sadly, still quite possible that the research community of this generation will continue to fixate on slowing aging the hard way, and we will miss out on rejuvenation technologies that will be developed in later decades to benefit our children or grandchildren.
But those technologies could be developed starting now. There's no barrier save for will and funding.