Encourage companies to only pay employees through banks by making it practically impossible to pay through cash. Expand money laundering laws so that banks are liable if they give out or take in physical cash, with short and hard limits to ATM's. Make it acceptable to have police confiscate money if a person carry more than a few hundred dollars. Just to give examples of those, a person was stopped by a routine police stop when they saw $350 and confiscated it on the concept that such huge amount of money was a sign of money laundering. A few further months ago a elderly couple (70+) had sold their car but could not put the 10 grand into the bank since the sale papers (including government signed transfer) was not enough to prove definitively that the money was still not part of any money laundering. Sweden invalidated all bills and coins made before 2015, forcing everyone to have them exchanged or put it in the bank which was why the elderly couple needed to put the money in the bank.
Add to that a heavy joint campaign between banks and government to paint any physical cash transaction as putting employees at stores at risk and that its a moral responsibility that everyone only use banks, and a strong decline in the availability of bank offices that handles cash.