IIRC, the grocery chain I worked for used to have an offline mode to move customers out the door.
Chick-fil-a has this.
One of the tech people there was on HN a few years ago describing their system. Credit card approval slows down the line, so the cards are automatically "approved" at the terminal, and the transaction is added to a queue.
The loss from fraudulent transactions turns out to be less than the loss from customers choosing another restaurant because of the speed of the lines.
The POS I work on also has this feature. Line busters take the order and payment but we have a toggle where you can immediately “approve” and queue it up. If the payment fails then the person handing you your food will see it on the order and ask you for alternative payment. It helps prevent loss and speeds up the line overall.