Something to think about: outstanding success for the SENS Foundation and its mission would look something like the assured availability of $100-300 million for research and development. That much money tends to build the successes and cachet needed to attract more of the same. To get to this point from where the Foundation stands now (a yearly budget around $1 million for the SENS Foundation, and an unknown but likely smaller level of unaffiliated funding for the same goals) might take twenty years of steady growth and success, with the end result being a substantial persuasion and conversion of the present research and funding culture for medical development. That wouldn't mean that the SENS Foundation would be a $100 million giant, or even necessarily still exist, but it would give rise to a diverse and competitive community that inherits the founders' values and goals - to defeat aging by building rejuvenation biotechnology more or less as presently envisaged in the SENS platform.
So what happens if a fellow with a net worth of $100-300 million becomes a zealot for the cause, overnight perhaps, and decides to put his net worth behind the SENS cause because without life and health, what is money? I use the world zealot in the best possible way here: someone who values the cause greatly enough to spend more time and money than most other people consider reasonable - but in this case is entirely justified, given the present harms caused by aging. But what happens if the community acquires such a zealot? To my eyes it looks like we would gain two decades of headway, and projects that would otherwise languish for twenty years would commence immediately. In a pattern of growth that is limited only by the level of investment - which is exactly where rejuvenation biotechnology is today - everything in the timing hinges on when the money arrives.
(It's a little more complex than this, of course, given that biotechnology is rapidly improving and costs for any given life science research project will fall rapidly over time - but you get the picture. Early money is still very much better than waiting).
The interesting question is why this doesn't happen: there are a fair number of very wealthy people in the world, and logic suggests that the best possible use for much those resources from their individual perspectives would to buy more life - since we are now in an age in which it is possible to make a run at buying significantly more life. What is wealth to the sick or the dead when it comes to it? But I don't think that this is a "why don't more people support engineered longevity?" sort of a question. My suspicion is that it is not just longevity science that looks in vain for wealthy zealots, but that in general any grand cause that people can feel very strongly about also lacks wealthy zealots. It seems to me that there is in fact little overlap between the small population of zealots for a cause, people willing to devote their working life and significant resources to a grand project, and the small population of very wealthy people, those with a net worth of $100 million and up.
We can speculate as to why this might be. For example, I might try to argue that the sort of person who can successfully run the long and unlikely process of becoming very wealthy is the sort of person who doesn't think about what they can do with money. They are not doing what they do for money, and the process is their passion. Someone who was a zealot for a cause would have stepped off that process long before reaching the possibility of attaining a very high net worth. Having a mere seven figure net worth for most people enters the territory of being able to prioritize volunteering over working, or funding a small mission in their favored charity. The temptation to break off and work on doing good rather than continually doubling down and doubling down on the process is ever there.
Or to put it another way, the passion for the process that will make a person wealthy takes up the much the same mental space as the passion for a cause: there are only so many hours in the day, and only so much attention that a person can give to any one set of information. So you are unlikely to see a person who has (a) accomplished the necessary devotion to work and process for a shot at becoming very wealthy, but also (b) put in the necessary work and process to become a zealot.
Or to put it yet another way, neither becoming exceedingly wealthy nor becoming a zealot are things that just happen one day out of the blue. They are each a fair way down their own different paths of effort, realization, and specialization.
This sort of thinking is the flip side of considering persuasion, high net worth philanthropy, and fundraising in general. It suggests that persuasion is exactly necessary because, for one, the odds of a funding source emerging from the pool of already-persuaded-and-fully-into-it supporters is pretty remote. Secondly, the odds are equally low that any particular high net worth individual or organization will suddenly get the picture of their own accord and begin pouring out money like water. These are different worlds, different views, different life courses that touch at few points - so people must set out to deliberately try to bring them together.