Every human grouping has good and evil people. The difference that matters is which group does the culture push to the top. In countries that are hellholes - corrupt people are incentivized to the top. In counties like the United States - until recently - basically good people have been pushed forward.
The WSJ had an article about the black farmers in Africa complaining about food aid. One quote was, “You can’t compete with free.”
Mexico is rich in natural resources, yet it is still a $#!thole, because the culture is corrupt. Bribery is expected in Mexico. Sure, it happens in the U.S., but the societal expectation here is that an attempt to bribe a cop will gain you a jail sentence, while in Mexico, NOT bribing a cop might land you in jail.
Consequently, the attitude in the U.S. is that hard work and intelligent investing will result in monetary success, while in Mexico, anything you can grab for yourself by any means is fair game.