Why are myths necessary if something works? It either works or it doesn't and the need for myths is a symptom.

Hard facts, social mobility is not rising by numbers. Myths are irrelevant when determining your chances. Social mobility statistics reveal your actual chances. Most people born into poverty will die in poverty according to the data.

Readers have a choice, to either listen to feel good myths or accept the data for what it's saying.

we find that lifetime earnings mobility has declined since the early 1980s as inequality has increased. Declines in lifetime earnings mobility are largest for college-educated workers though mobility has declined for men and women and across the distribution of educational attainment. One striking feature is the decline in upward mobility among middle-class workers, even those with a college degree. Across the distribution of educational attainment, the likelihood of moving to the top deciles of the earnings distribution for workers who start their career in the middle of the earnings distribution has declined by approximately 20% since the early 1980s.

This decline is going to effect your odds of financial success and if you are in vulnerable demographics your odds are decreased even more. Low odds doesn't mean impossible but it takes a very exceptional person to beat the odds and hard work alone isn't going to be good enough.

References

1. https://www.theatlantic.com/business/archive/2015/07/america-social-mobility-parents-income/399311/
2. https://www.theatlantic.com/business/archive/2016/07/social-mobility-america/491240/
3. http://equitablegrowth.org/working-papers/the-decline-in-lifetime-earnings-mobility-in-the-u-s-evidence-from-survey-linked-administrative-data/