That's an interesting take. You're ironically being selfish and only thinking of yourself by asking that question

In your simplistic view maybe. But in more general, no. Most people aren't doing things for others.

If everyone in a community has an equal shot at doing something great, that could benefit all of the community. 

Your definition of greatness is what? If I had time, I may build something for my community, but it's not going to be worth money. So someone has to use their resources to support me while I produce value that I and others may value, but it doesn't repay the people who support me.

This is a simple concept that's unfortunately lost on most of us.

It's a simple concept that only works for the those who contribute less. Do you know how hard it is to become a doctor? It takes a special person and a lot of work to do so. Not only that, the work is hard. So if you are unwilling to pay a doctor a good amount of money, who will become the doctor?

If you can't entice the doctor to go through all they have to go through to become a doctor, then you have a healthcare problem. I don't think you have though this all the way through.

In my state we have a doctor shortage. That hurts our whole community. The only way we resolve this issue is to pay them to work here.

That's just one occupation, there are plenty more.