What I have noticed is that CDs had lower yields than Treasury bills of the equivalent duration, until the bank runs happened. I think a lot of banks suddenly increased their CD rates just because they were also fearing a bank run. CDs lock in depositors' money a lot more. When the bank crisis subsided the CD rates went down because banks didn't feel a need to attract so many depositors.

Disclaimer: I bought a 5.4% CD a few days after the collapse of SVB.