Need to obtain debit card facilities

I stood in a long line (because of the pandemic restrictions) to buy some savouries. When I eventually got inside to order my goods, I was told they don't take cards. Why don't they take cards. Now my question is, for a business who is so busy, why don't they take cards and trust me they are beyond busy. In this day and age, I would expect a business especially a busy one to have debit card facilities.