The keyword is Prodigious so not everyone will get to that level. If your net worth is 1 x Age x Annual Income / 10 then you would be an Average Accumulator of Wealth. If it is < 0.5x, then you would be an Under Accumulator of Wealth.
Also your home equity is included in your net worth, so if you have a 300k 30 yr 4% mortgage with a payment of $1450/mo, around $450 of that in the beginning is going towards the principal. Plus if the market value of your house goes up, that will also increase your net worth. e.g. 375k house x 3%/yr = 11250/yr or 937.50/mo.
If you get your house paid off early, your monthly expenses will drop dramatically, so not only will you be able to save and invest much more of your income, but also you won't even need to have as much saved for retirement. e.g. 1.43 mil x 4% = 57,200 - 5k taxes - 18k living expenses without a mortgage = leaves 34k for discretionary spending which is plenty.