How many people who could have become great scientists, engineers, or inventors instead have to grind out an existence planting and farming grain or bussing tables in a diner or some other job?

It's not so much an issue for those people who came from poorer backgrounds and became scientists (though there's still a question of whether they could have been better scientists with better early educational support), but it's a bigger issue for those who never got that chance by an accident of birth.

I don't support equality of outcome as a desirable goal, but I do support equality of opportunity.