Let's start with Pasteur. Few would deny that the adoption of rigorous sterility in medical practice, arising from Pasteur's germ theory, saved an absolutely astronomical number of lives. However, any reasonable estimate of the lives Pasteur himself saved must take into account an estimate of how soon his successor would have come along. It wasn't a matter of whether lives would be saved, but when.
So it is with today's progress against aging, but more so, because we have an additional dimension of uncertainty. Pasteur's advance did not require development time: as soon anyone wanted to be more hygienic in their medical practice, they could be. In the matter of aging we are today faced with a very large research agenda that must be completed before we can deliver actual therapies, and, as is the nature of research, we do not remotely know how long it will take. Pasteur's insight led to saved lives starting almost at once, but no amount of additional effort injected today into anti-aging research will save any lives at all for quite some years. And additionally, the date at which such an effort would start saving lives is highly uncertain.
Which brings me back to funding. Time and again I encounter people (high net worth and otherwise) who are provisionally interested in funding anti-aging research, but whose interest, when push comes to check-writing shove, is somehow contingent on being (with substantial probability, anyway) beneficiaries of its success. How crazy is that?
Altruism is rare in comparison to self-interest, and people want silver bullets now. As illustrated, even a vague hope of the existence of a silver bullet, somewhere, perhaps soon, will cause people to pass over the best of present opportunities, things that require work and are no sure thing. Everything worthwhile requires work in this life, and I've certainly never seen a sure thing in any of my endeavors. That is the way most people think, however.
Those who choose not to support de Grey's vision for rejuvenation biotechnology, the work organized by the SENS Research Foundation, are indeed passing on the best shot at accelerating progress towards the medical control of aging. No other coordinated program is anywhere near as promising. True enough, the stem cell and cancer research communities are making some progress on their slices of the overall rejuvenation toolkit, largely as a side-effect of being very large and very well funded, but much of the interest in intervention in aging research remains focused on classes of potential treatment that cannot plausibly do more than slightly slow down the aging progress. Even achieving that modest goal will be painfully expensive, slow, and uncertain because it requires safely reengineering the operation of our metabolism so as to slow down damage accumulation. Metabolism is fantastically complex and decades of work yet remain to make even a dent in the vast unknown areas yet to be mapped. In comparison, SENS focuses on damage repair without metabolic alteration, and far more is known about the damage that causes aging. Thus the best approach is for the damage of aging to be repaired, not merely slowed, yet all too few organizations other than the SENS Research Foundation are trying to make that a focus.
We live in a world full of individuals who would write checks to further rejuvenation research and the development of treatments for aging if they could see it was a sure thing, if they could be certain that they would benefit. This is some subset of the majority of people who would certainly choose to buy rejuvenation treatments if they were widely available today. Unfortunately the size of bank accounts tends to scale with age: the majority of individuals wealthy enough to fund significant chunks of a research program are unlikely to benefit personally from supporting medical research into methods of rejuvenation. They don't have the time to wait for the results and the cycles of development and the clinical translation of research and so forth. So they choose to do other things with their funds. Progress depends, as ever, on the unreasonable minority possessed of altruism enough to care more about the rest of the world than themselves, or given drive and fortune that made them wealthy enough while still young enough to think that they might benefit.