It’s not a low interest for everyone. But here its like this: of you pay, fine, at the end your money (invested) is yours to do what you want. If you don’t pay, the bank will keep your investment as payment. The investment is the way the bank assures you are going to pay. If you can’t put anything in the deal (car, house, investment) you’ll pay full interest, which could be anything. I see clients getting 6,5% interest all the time

Can’t say much about US, but in my country if you get 100k assured by an investment of 100k, for exemple, you pay 1.2% in the loan, but the investment keeps going up by 1.1%. So you pay 0.1% for the 100k. A LOT less that you’d pay if getting your own money back