Card is a permanent %2+ tax, how does it compare?
A small coffee shop can get by with a $129 cash drawer hooked up to an iPad and a manager spending a few hours per week counting money and visiting the bank. A large store like Walmart can easily spend $100k+ on all of the equipment for cash handling in addition to having to contract with an armored car company.
Over a year, it's perhaps 4 hours/week x $30/hour x 52 weeks/year, which comes to over $6,000. That's real money for a small coffee shop.