I get the thought experiment. This idea is something that floats around now. Borrow against your bitcoin and never have to pay the loan back because Bitcoin goes up year over year. So as Bitcoin goes up in fiat price year over year, you can re-collaterize your loan and never have to pay it back. I think that strategy works now but in 2150 when fiat no longer exists and cryptocurrencies and tokenization are the base layer of the financial system, I think you must trade your bitcoin at that point.