Caffe Nero is a chain in the Boston area (and elsewhere) which has no tipping when using a credit card. Most locations have a tip jar for cash, bud no option to tip. It certainly helps me think that they’re getting paid a decent wage since they’re not prompting me to tip automatically. And the employees generally seem happy, and payment goes faster since there’s no stuttering and thinking over the tip step.
The same simple credit card machines are used at Qdoba, but there they ask for a tip, even when coming in to get a bowl and doing takeout. Not unreasonable, but the difference in experience and expectation is pretty wild: coffee sometimes takes as long as it does to put a burrito bowl together, yet one expects a tip and one does not.