I wonder that your bills or coins called "bitcoins" that can you pay for other payments not only using a internet but in handling it and paying at the counter ?
No need for physical coins nor bills just pay with your smartphone. Scan a QR code, check the amount, click send, enter password, wait a second, done.
But when you dont have a smartphone ? and then the payment needs was a bitcoin ? how you buy it if you dont have bitcoin and make it a bills or coins ,