The value of the collaterals of the loans in all functioning currencies is much greater than the value of the physical cash. Thus if you hold the cash, you can

The value of the collaterals of the loans in all functioning currencies is much greater than the value of the physical cash. Thus if you hold the cash, you can attempt a corner in order to obtain a large fraction of the collateral: you hold the cash so that people can't get it and default on their loans. Thus you obtain a large fraction of the collateral, something of enormous value. What central banks do when you try to do this is that they start printing money, thus this scheme can be stopped. If there's no central bank to do this, the self-interested cash holders could potentially coordinate something like this. I think the cause of yield curve inversion can be something of this sort, because it can mean that people expect a crash and want cash on hand to buy assets once it has happened, so they don't want to lock their money up for six months, even if the yield is quite high.