It varies per game, but my most common use is to replace the thumbstick clicks. I don’t like how it feels to click in the thumb sticks, feels like I’m adding extra wear and tear to them.
In first person games, I’ll often bind jump, sprint, reload, and melee to the back buttons so I can move and aim while performing those actions.
If the drink is filled to the same level on the glass, then less ice must mean more drink, right?
Unless you fill the drink first, and then add ice, in which case the drinks with ice would have higher water levels then those without ice.