Considering how little the minimum wage has gone up, even as inflation has ballooned, is it really entitlement for expected tip percentages to have risen too? People in these incredibly necessary service jobs are not being paid enough to survive. I don't love that whether service job workers take home enough to pay rent and eat is dependent on the whims of the fickle public, but unless there's pressure upon greater forces to make the minimum wage also a living wage, that's just kind of how it goes.
I am very VERY far from FIRE and I tip 20-25% in every tip-appropriate interaction that comes along, sometimes higher if the service was exemplary. I don't say this to brag, although this is a habit that I had to work hard to cultivate because I too was very very stingy and it took a lot of mental reframing to pull away from that mindset. These days, I try to come at it with a perspective of gratitude, and I think that helps with severing the push-pull feeling of 'are they feeling entitled to $$$' and 'i'm paying X amount for this service, not X + 25%, i feel pretty cheated.'
Part of it is in gratitude for my luck and for what I have: I have enough that a few dollars here and there will make a difference only to my investment accounts, not to whether or not I can pay my rent this month. It's also out of gratitude for the people out there doing the job so that I can have my quick and convenient ride to the airport, trashed swept off the streets, my hotel bedsheets changed, or a hot coffee in my hand on demand, food ferried to my table with a smile and the dishes washed out of my sight. That they are just doing their jobs doesn't make me any less glad for the work that is done, and how it makes my life easier, more convenient, and more pleasant.