This is absurdly false. The serfs can become kings as evidenced by newly minted millionaires every year. However, the reverse is also true as there are plenty of fortunes lost as well.
That's about forty times my annual salary, ignoring expenses. Living like a miser for my entire working life, I could become a millionaire – though not a multimillionaire.
The odds of a poor person becoming a rich person in America is extremely low and socioeconomic mobility in the US is getting worse all the time. I'd guess that most poor people have better odds of getting hit by lightning. A lot of new millionaires are property owners. Anyone who gets their money from real estate is not a serf.
