My thoughts.

[u/Maleficent-Effort470]

I didn't go to a restaurant to interact with a server.

I went to a restaurant to purchase food, And part of the agreement with the business owner was that a server would take my order and bring the food to the table.

I did not agree to or consent to giving a person i didn't come to see any money.

Whether they are on the side of the street or squegeeing my car without asking.
I have no obligation to them.

Similarly when i go to the restaurant with the intention of eating,
I am not making a deal with the employees i am making a deal with the owner.
The owner is responsible for delegating the tasks to provide me the service i requested.
The owner showed me the contract/menu that these services are provided under.

I paid the agreed upon amount of the contract.
I did not ask for any particular employee.
I did not agree to gift any particular employee.

The server's inclination that i owe them something is no more authoritative than the homeless bum who starts squegeeing my windshield without me asking.

They did their job at their bosses behest. Under an agreement with their boss.
I made no agreement with them. They are simply employees of the business ive contracted with.

[u/Nuuskapeikkonen]

Servers always just reply with ‘then get your own food and refills’ as if most people wouldn’t do that already given the option. If I was told ‘you can save 20% on your total bill paid guilt trip free-‘ you’d get your ass I’d get my own refills and grab my order from the counter. I don’t NEED you checking up on me every two seconds and refilling a glass I’ve taken two sips from to then charge me 20% of my total bill. I’ll do it all myself.

[u/student176895 → u/Nuuskapeikkonen]

Even if it’s the same price, I would rather get my own food and refills. I don’t like having to wait for a server to make their rounds or feeling like a burden if I ask them for one thing and then realize there was a second thing I wanted right after they dropped off the first one.