Very accurate analysis.
By using collateral to secure debt, billionaires can leverage their worth into tax-free loans and use those loans to build even more value that remains untaxable until they actually sell it. Buy why sell it when you can just put it up for collateral and take out another favorable loan?
It's one of those "got to know the rules to win the game" things that most of us never even think about :)
Another is getting taxed and then spending whatever is left, versus spending / investing then paying taxes on the remainder ... if at all ...