Last time I gave a tip, the pizza cost like $19 and I paid with $20 bill and I didn't want change. We don't have 1 dollar bills, just coins.
This just an example.
Now that we pay with cards there is no tip.
BUT, I've read that some places try to sneak it in by having it as an option.
This would be on top of their already good salary. Tip is 100% a bonus.