Think of it this way, if I had borrowed $40000 to buy my wife’s minivan, I would have saved 7 bitcoin. I effectively bought those 7 Bitcoin over time with each loan payment. So those 7 bitcoin were dca’d into over say 5 years. My return over 5 years is undoubtedly less than had I just held those 7 Bitcoin, because my cost basis moved up, but remember we are comparing against having sold the bitcoin, not merely hodling. After paying off the loan, you have 7 bitcoin and a vehicle.