Wrong. In a hard currency economy, interest rates greater than the money supply expansion are not competitive and never taken up by the market, (unless the debtor is extremely risky and then you can basically kiss your BTC's goodbye (i.e. a loan to your useless, unemployed brother-in-law cause your sister is screaming at you).)
The gold supply expansion from mining is around 2.25% per annum and it is almost impossible to get gold loans at rates that high.
In the long term, since BTC expansion goes to zero they will be basically interest free ... if you can find a risk-free debtor. More likely loans and debt will become less widespread and joint ventures will become more the norm where the loaner really does have an "interest" in what you are using the money for and doesn't just collect the interest cause he created the money out of thin air.