Yeah agreed. Even if cashiers had a tracker for bills you still have general population chaos. Like I take 20 out of bank (tracked). Say I paid a friend and they bought something (tracked) then you have some rudimentary contact tracing/location, however: I could take out 20 (tracked) and ask a homeless guy if he'd give me $18 in change, bills and coins for a $20.
Now my transactions just disappeared, if the homeless guy immediately buys something you have some tracing and location, but you know how life is: money slips from his pocket, the wind blows it a few blocks away, a guy from out of town finds it and maybe mails it to a relative as part of a birthday card, that sits in a kids piggy bank for a year. Spends it and it's tracked...but that data connection is a mess to try to work backwards to the withdrawal