That is a very good book. In it he uses a “wealth Formula”. It is: your net worth should be greater than : your Age X Salary / 10
He found that this line separates the good accumulators of wealth from the poor accumulators of wealth.
I have been watching that number for years and just this year crossed over to the good side (it is almost impossible to do at a young age).
The people you are talking about probably have a net worth close to zero.
A big mistake I see people make is when they count home equity as part of their net worth. Yes, you can sell your house today and have that money in the bank. But then you are typically going to take that money and find another place to live! Also, people tend to overstate the true market value of their home.
If you are on the good side of that wealth formula (Age x Salary / 10) without counting your home equity, you are in pretty good shape!