I distinctly remember articles about coffee shops and similar going cashless in a few different countries ( UK, France at the very least) because managing cash costs time and money ( it needs to be counted, stored, safely transported to the bank, etc.) and doing card-only payments comes out cheaper for them.

Banks usually charge .9-1.5% for cash deposits, plus staff time to count, insurance, safes, etc.

A debit card costs .10c and no %. A well implemented cryptocurrency would be even less.