Look up the stats on inherited wealth. It’s actually difficult to rise far above the socioeconomic status you were raised in. The higher the socioeconomic status you were born in, the harder it is to drop as well. It’s because capital can be invested safely to maintain wealth, but it’s hard to start without capital and gain wealth.
It’s not uncommon to go from middle class to millionaire status, but almost impossible to go from middle class to billionaire. What % of billionaires started out as multi-millionaires?