When we first went to the states (20+ years ago), a standard tip was 10%, although the exchange rate was horrendous, it was liveable extra cost (even though the server was just basically doing their job), went again in 2017 with family, it was then up to 15% and this was the low option on the terminal, with 20, 25 & custom available). When back in vegas last year, 18 was now the starting point.
I've seen it occasionally on terminals (notably at high end restaurants and ones in popular tourist spots in Christchurch), but alwasy bypass / enter nil. Really don't want to go down the path of being expected to tip, just for someone to do the thing they were hired to do to begin with.
I have no doubt hospitality is a grueling industry, late hours and dealing with customers (especially difficult ones) can't be much fun, but it should be up to the employer to charge a fair price for the food to enable them to pay a fair wage to the employee



