> Would the vast majority of them invest years of their life in it if it only paid the same as getting a normal job?
Empirically, given that academia pays much less than working in the industry, yes.
> the vast majority of productive people do the important everyday work
I beg to differ. Most productive people do completely irrelevant everyday work: optimize or sell ads, or play wall-street poker with other people's money. Very few people do the actually important work (e.g. garbage collectors, farmers, scientists, teachers).
I don't think the answer is a simple "No, they wouldn't invest those years of their life"
It seems in my experience that most people who invent life changing technology don't do it for the money; they do it because they like to create. Humans have an innate drive to create new things. While I think it makes sense to reward people who contribute to society, those rewards don't have to be unlimited.
Devil's advocate: the vast majority of productive people do the important everyday work, but don't perform major improvements in the state of the art. What about the inventors of life-changing technology? Would the vast majority of them invest years of their life in it if it only paid the same as getting a normal job?