It won't though. A screen on the card terminal is free - if just 1% of people misclick the button and pay a tip, the company still wins.
> A screen on the card terminal is free
... consulting companies developing the terminal entered the chat ...
(just kidding, I agree with you)
A restaurant is fundamentally selling an experience. These screens do not improve the experience. Therefore, they have some cost to the business. The question is whether the cost is recuperated.