You and practically everyone else, a key reason general level of service quality has cratered in the past decade or so. If they get the same tip regardless, if you're trained to expect it as your due just for being there, what's the incentive to be nice to the customer, or even cordial?
My buddy I referred to earlier gives tips approaching 30% regardless of the situation, whether it's someone serving him multiple rounds at a decent restaurant, or someone who merely opened the beer can for him at a ballpark grab-and-go. I mentioned to him once I found that interesting, in practically those exact words. He basically tip-shamed me in reply. That was the end of that conversation for good and ever. Do what you want, Dan, I'm still leaving a single dollar bill for the beer guy at Wrigley and that's it.
All I will say here is that other countries have figured out how to have restaurant servers make a decent living without shaming customers into tipping them, instead baking their income into appropriate menu prices and paying them standard wages, and they all seem to like that just fine. 🤷🏻♀️