Except for the whole issue that growing economic output denominated by a physical asset with a fixed supply is inherently deflationary, which in itself renders any institution that charges interest to lend said asset proxies useless.
Why deposit anything in a bank, when you get a real return by stuffing it into your mattress? Or the funner question, why buy anything now when you get buy it later less?
Personal question for ya - feel free to be honest. You have no formal background and/or education in economics and mostly found out about this stuff thru wikipedia and/or blogs and youtube right?
Answer to your question, I have a degree in finance and took all the economics electives I could because it interested me.
Feel free to be honest with me, you got a master's in economics and decided you couldn't be useful to any price discovery in the markets and used your bachelor's degree in computer science to rip people off through quantitative trading algos?