The modestly compensated "average Joe" can also get near that number by contributing the max $19,500, getting the 100% employer match of $19,500, the 5% employer match of say $4000... (we're up to $43,000 so far)... 

**...and then, make it a Roth 401(k)** instead of a traditional.   

A dollar in a Roth 401(k) is worth more than a dollar in a traditional, because you're bot having to bring the tax money into the retirement account. The taxes are paid externally to the account, and the money in it is all yours.  If you're in a combined (state + Federal) tax bracket of 28%, $1.00 in a Roth is worth $1.39 in a Traditional.  

(After you pay 28% taxes on $1.39, you are left with $1.00). 

So that $43,000 Roth contrib is as good as a $59,722 Traditional contrib.