How much money would it take to engineer biological immortality for at least half of the world's population, within 20 years, with 99% confidence?
So we can't suppose drawbacks that involve 'someone not liking it'.
How about the drawback of "starving to death"?
Is voluntarily starving to death a drawback?
How much money would it take to engineer biological immortality for at least half of the world's population, within 20 years, with 99% confidence?