There are many US individuals who have accumulated total assets in all of their retirement plans combined of in excess of $10 mil, and many are way in excess of $10 mil.
This "Tax Deferrals Gone Wild" is another illustration of how most in the US Congress continue to legislate only for the wealthy.
My recommendation here is that once an individual has accumulated total assets in all of his retirement plans of at least $10 mil, that all of his subsequent earnings in these retirement plans will now be taxable for US Federal Income Tax Purposes.
All of the money raised here should be used to reduce the US Debt.