Fifty or sixty years to cash out at that rate, so you might still be alive.

Depends on your age, but it would take 19 years, 3 months.

Has there ever been a billionaire that managed to “spend” all their wealth before dying?

I'm guessing you got this idea from one of those "how rich people dodge taxes" articles? It's a terrible idea, because you still remain exposed to bitcoin. If you borrowed 1M dollars against your 2M in bitcoin holdings, and bitcoin crashes, you'll get margin called and be expected to pay that 1M back.

That only works if the loan snapshots the BTC price at the time of the loan.

In the case of the most naive lender in the world who does this, you will be bitten by their incompetence in some other unrelated way almost immediately.

In the case of any competent lender who knows anything about Bitcoin, they would go "way too liquid" and "haha nope".

</uninformed_commonsense_guess>

Isn't that the worst thing to do? I assume that a bank knows that bitcoin is volatile so the terms of the loan would include their ability to call the loan if the value of the bitcoin collateral drops too much.

So you could have your $100M loan in the bank one day, and have to pay it all back (including what you spent) after a bad bitcoin day.

Only if you want to tap into like 10% of your BTC. You'll also have to make sure you put some of the loans to good use in the real estate market for example.