Since you're talking about Austrian economics, this is what Rothbard has to say about interest rates:
"Perhaps more fallacies have been committed in discussions concerning the interest rate than in the treatment of any other aspect of economics. It took a long while for the crucial importance of time preference in the determination of the pure rate of interest to be realized in economics; it took even longer for economists to realize that time preference is the only determining factor. Reluctance to accept a monistic causal interpretation has plagued economics to this day."
This is an excerpt from page 389 of "Man, Economy, and State" - https://cdn.mises.org/man_economy_and_state_with_power_and_market_3.pdf
Your suggestion that perhaps a jury of random citizens should select the interest rates is a fallacy, as was already argued by Hayek in his "The Use of Knowledge In Society" - https://www.econlib.org/library/Essays/hykKnw.html
The interest rate is the price of money, so select group of people, however skilled or randomly chosen, should "decide" it.