Your assets tend to become more valuable over time, which allows you to borrow more money to pay the interest and give yourself spending money. Eg, suppose you

Your assets tend to become more valuable over time, which allows you to borrow more money to pay the interest and give yourself spending money. Eg, suppose you have $10M in assets and borrow $200k against it. Next year it's worth something like $10.7M on average, you get charged something like $8k in interest, and you borrow another $200k to spend. So long as you leave enough of a buffer against volatility and the rate of growth of your assets is high enough, you can just borrow money indefinitely against appreciating assets. People did this in the run-up to the 2008 housing crisis with homes, too. Take out a loan, cash-out refinance later when it's worth more, end up with a house you've taken more cash out of than put in.