When I worked in food service and in the mailroom, the uglier touchscreens were always easier to work with. They were color coded with bright, contrasting colors, making the boundaries between numbers or items very obvious. I found that the colors reduced mistakes. I’d usually tap the right items after barely even glancing at the interface. After a while, I’d only check the screen for mistakes at the end of the process, before submitting an order or printing a receipt.
Most touchscreen interfaces don’t use high contrast colors or locked, static buttons for basic functions. They bury actions under multiple buttons, and this leaves us dangerously hunting for the right button while trying to drive, or our frustrated passengers trying to help us get our phone connected via Bluetooth.