Relative to the peers in their own country they usually do. Globally, yeah people get shit hands. That is why doctors leave their countries, go through the trouble to relicense and practice in the US.
What about people born in the wrong neighbourhood or even the wrong family.
I have a hard time beleiving IQ is a strong predictor of income. Anecdotally I personally know a lot of dumb people who make a lot of money and intelligent people who don't.
If anything I'd say social skills are probably a better predictor of income.
I know a 5'3" guy who played in the NBA.