Without those challenging backgrounds having made them who they are they may have never achieved greatness if they had everything given to them the same as other children.

That's one way of looking at it. Another way of looking it is to wonder just how many kids will never achieve greatness because they didn't get everything given to them same as other children?

Look at the most successful athletes in any given sport. How many them actually come from deprived backgrounds as opposed to the number that got all the coaching and equipment and nutrition and time off from school/work they needed?

Just because suffering can breed excellence doesn't mean it will -- and it sure as hell shouldn't have to.