First off, if you're paying 3% interest on a collateralized loan where the collateral is earning 5-8% interest (like stock market returns) you both don't pay taxes and come out ahead at the end of the year.

Second, I know people that are firmly working class (though earn decent money) doing buy borrow die with real estate. Its pretty much standard among the wealthy.

Further, using equity lines of credit (ELOCs) you can multiply money. The closest a normal person will get to an ELOC is a HELOC, or a reverse mortgage, which are tightly controlled. Rich people have a lot more freedom.

Say you have 100m stock portfolio. You take out an 80m loan using it as collateral, and then buy a business for that 80m. Then you use the 80m business as collateral to take out a 60m loan, to buy a jet. Then you use the 60m jet as collateral to take out a 40m loan, and use that to buy a yacht. Then you use the 40m yacht as collateral on a 20m loan...and you suddenly have 280m of leveraged assets under your control paying for the interest, and a tax free 20m loan for pocket change. As long as you don't sell the original stock, you don't owe taxes on any of that.

Edit: and there isn't a single civilized country in the world that allows inheriting debt. That's the whole point. You transfer the assets to your heirs and die in debt with no assets. Nothing to tax, nothing to reclaim.