I never saw a tip jar at a DD drivethru nor at the counter. I don't
tip if I'm having coffee passed thru a window, or picking up a
called-in food order.

I will tip tho at optional buffets where the wait person delivers
water, learns if you want the buffet or food from the menu, and has to
present the check. Otherwise, he or she could in theory have an
entire morning of b'fast buffet takers and get nada. They have to
make a living too.

bill payt-- are you angered if you have to stand in line at a
cashier's position or do you think it should be the waiter's duty to
handle the payment?