Like others said – credit crunch means that banks are less eager to lend, their demand for your money is lower. Lower federal funds rate means lower “prime rate”, and many kinds of loans are tied to the prime rate (credit cards, auto loans, HELOCs). Banks get poorer returns on those loans they do make, so they have to lower yields on savings accounts and CDs.

On the other hand, savings rate is up. People are not spending their money as freely, even large chunks of stimulus checks end up in savings accounts.