I have some data on this... Though not exactly what you asked (but you can back into it).
There are currently ~365,000 bank tellers in the US (2021 data). That's down from ~550,000 in 2010. Huge drop from 2019 to 2020 (pandemic), so not sure if that number will creep up when we have '22 and '23 data.
Average # of monthly teller transactions:
1992 - ~12,000
2002 - ~10,000
2012 - ~7,500
2022 - ~4,500
Most common transactions using a teller: depositing cash and depositing a check
Both of those transactions are becoming more often automated, but for sizable deposits people still prefer to use a teller. Which I get. If I am bringing in a big bag of cash, I'm not sure I want to just feed it into a sort of ATM and hope it gets it right (even though it'd probably be more accurate than using the teller).
Teller pay also up significantly...
1992 - ~$8/hr
2002 - ~$12/hr
2012 - ~$15.50/hr
2022 - ~$21/hr