WTF are you talking about? If you provide me a good or service I can pay in cash. That is how we pay debts. It's legal tender. No business can refuse legal tender at least in these states:
Read Stateline coverage of the pandemic’s effect on the economy. DENVER — After a constituent called Colorado state Rep. Alex Valdez last spring and complained that some local businesses weren’t accepting cash, the Denver Democrat started noticing cashless businesses everywhere, from restaurants...
stateline.org
A problem lies in the fact that almost 10% of people don't have a checking account and only deal in cash. You are now discriminating against such people. What about the elderly? Most of those don't deal with credit cards and only do cash. You can't discriminate against them. My mom STILL pays cash or writes a check everywhere she goes. She is the one holding up the line at Wal Mart. If Wal Mart stopped taking cash she'd walk out. She'd have no choice.
What about the 16% of all Americans with bad credit that can't get a credit card? Why are you discriminating against them?