Here’s what just a bit more than 10 seconds of Googling reveals.

• Research reported in the book, “The Millionaire Next Door” states that 80% of millionaires were self-made. The book was published in 1996, so the research likely took place during the early 1990s.
• According to a Washington Post article from 1992 (https://www.washingtonpost.com/archive/politics/1992/07/11/number-of-us-millionaires-soars), there were about 2.1 million millionaires in 1991, while the US population that year was about 253.5 million. That made the fraction of millionaires was about 0.8%. Those 8 out of 1000 were responsible for ~20% of the non-self-made millionaires.
• The likelihood of becoming a millionaire if your parents were millionaires was thus about 31x greater than if they were not… (20%/0.8%)/(80%/(100%-0.8%))=31.25

That’s why I believe my assumption that mobility isn’t a major factor, while certainly not rigorous, is at least plausible.

If you’d bother to post actual data and/or research that prove my simplification is so egregious that it renders my whole argument false, I’ll be the first to admit my mistake and correct it.

On the other hand, if you continue to simply assert that I’m lazy, dishonest, etc., I’ll respectfully allow you to bask in your self-certitude and move on with my day. You’re more than welcome to simply ignore whatever I write as obviously not worthy of your time.

I’ll treat further writings from you with the same (until and unless you post actual data and/or research that support your assertions).