Ice
Getting ice in a drink is so hard. Cup sizes are so small. No-one does free refills.
No, we generally have smaller cups. They contain less ice and more actual drink than many larger cups you get from the USA.
Because we get more actual drink, there’s less need to get refills. There are places that do it, but not many in this country. Free refills are not free – you have already paid for it.
Getting a drink that is full of ice does not mean you are getting anything better. You are paying for frozen water. You won’t eat or drink it. You will throw it away and it will melt and make puddles on the floor.