Cash must be accepted. It is the only form of payment (besides cryptocurrencies) where the individual does the payment. Other forms are merely large corporations/institutions using their financial clout to signal that they will pay for something in the future. And those corporations always have perverse incentives to both sell your purchasing history to anyone that wants it as well as enact financial embargoes against arbitrary people/companies whenever even slight political or social pressure is applied.
Only accepting corporate or institutional payments is racism against non-corporate persons (humans).