A question for the people who say they tip for good service, what are you counting as 'good service' because it's something that's quite rare in my experience.
Things that are 'bad service' that seem to be fairly standard in a lot of restaurants, both independents and chains
Giving you a crap table because it suits them - on top of other diners, near the toilets etc.
Asking you what you want to drink when you've barely sat down.
Disappearing for ages when it's clear you want to order or pay.
Not bringing change back when you've paid in cash because they're hoping it's a tip even if you've put in say 3 x £20 notes for a £45 bill.
Not having a clue who ordered what when they bring it to the table
Interrupting your conversation or waiting until you've put food in your mouth to do the 'check back' but then panicking and no knowing what to do if you say anything other than being satisfied with the food.
Failing to bring the right drink despite being asked three times and lying about what the drink they've brought actually is.
Clearly just going through the motions/upselling when you still have food and drink/haven't finished your main so are unlikely to want a dessert.
And that's without getting onto taking forever for food to arrive, half the menu being unavailable or it coming out at very different times or being badly cooked or not what you ordered.