I worked in the hospitality and tourism industry for numerous years and 15% is standard but not everyone does it there is apps you can get for your phone to see how much you need to tip after total including tax.

Things ones gotta recognize is that in restaurants it’s not always the servers fault the food comes from where the kitchen and servers can have a section up to 6-10 tables. If it sits to long in the window and no fault of the customers because sometimes the communication is key from all parties involved.

Something like a medium rare steak takes less time to cook then well done steak. The well done steak goes on first because it takes the longest to become less like meat then medium rare steak. But kitchen does there best but that we’ll done steak holds the rest of tables food up because they want everything to go out together.