I don't think they see the tip amount until after. I assume he came back to the place to fuck up the chair?
You earn a tip for going above and beyond
Not really. Go back a few decades and there were parts of America where money was put on a table before orders were made. (Some older people still do this in the South). This is part of the philosophy that TIPS = "To Ensure Proper Service"
...and yea, that is all due to the asinine wage laws .. but restaurants also operate on super thin margins for the first 3~6 years (if they survive). The counter argument for tipping is that the service/hospitality industry can provide a lot of fast cash for college students who are willing to put up with it. 🤷