Need to get a thick skin against the tipping culture in US. I make it a point to not tip at all in the US. I've had wait staff argue with me, called a cheapskate, countless eye rolls and murmur swearing. I don't care, I don't live there, travel there for work occasionally. I detest the tipping culture there, it's gone from optional for exceptional service to being mandatory (without it legally being mandatory).

If in the mood to engage with the wait staff, I tell them their managers/corporate is responsible for their pay and shouldn't be on the customers to cover the shortfall