If your smart contact is truly reliable and anyone can lend on it at a rate of their choosing, and all loans are fully and perfectly collateralized, the natural

If your smart contact is truly reliable and anyone can lend on it at a rate of their choosing, and all loans are fully and perfectly collateralized, the natural interest rate is exactly the risk free rate. As above, for ETH I think that ends being the return on staking, minus the costs of actually running a staking node - so pretty close to zero?