I think the other thing is that it's not only expensive to become a doctor, but fairly grueling as well. Some number will still do it for altruistic reasons, si

I think the other thing is that it's not only expensive to become a doctor, but fairly grueling as well. Some number will still do it for altruistic reasons, similar to how you get some amazing teachers despite the terrible pay, but it'll probably be a lot harder for most extremely effective people to justify doing that over another, more lucrative field. One thing that might help is eliminating the undergrad requirement before medical school.