Unpaid interest by US banks is banking sector profits. If US consumers could maximize their interest through investment directly in short term US treasuries, banks would need to go to the debt markets va underpaying potential interest to demand deposit account holders.

The Federal Reserve has denied a narrow bank from attempting this (to support US commercial bank interests), but it’s unlikely they can stop stablecoins.

https://www.chicagobooth.edu/review/safest-bank-fed-wont-san...