- There are not enough Billionaires to meet your needs, statistically you'll need quite a few to find any decent cures. Especially with 30 teams in play on each case; figuring out "what worked" is a bad numbers game in that case.
- Science shows there is unlikely to be one "magic bullet" for cancer, which makes it hard to cure individuals and then take that science into a wider populace; "something here worked, but does it work generally?"
- Cancer treatments are harsh and invasive - by design! 30-40 competing drugs is unsustainable, you would be, to put it mildly, royally fucked. So death could come simply by exhausting the body with treatment, as easily as anything else.
- You invoked Godwin's law, which is never a good sign.
I agree with your general premise; which is that it takes too long to iterate ideas into actual production. But the reason that scenario exists is not just "quack medicine" and other hopeful (but useless) remedies, it is for the case of "oh shit, I just killed a million people because we didn't investigate long term effects".
And that is where your theory really fails; because you are trading an unknown collateral now, for an unknown collateral in the future. I'm not arguing against either as a good or bad thing; but it does highlight the fatal flaw in the argument "you are killing X people right now by not releasing/iterating fast enough"