1. It's far easier to populate a dishwasher after feeding e.g. a family of four than it is to immediately wash all of the utensils, dishes, bowls, pots, and pans. This task is usually delegated to one member of a household in the US.
2. "Contrary to popular belief, the dishwasher is designed to be more efficient than the way most of us handwash dishes. According to Energy Star, certified dishwashers use less than four gallons per cycle. The sink uses four gallons of water every two minutes. But just how many dishes do you need to make the dishwasher a more water efficient choice? In a recent study, Cascade found that the average person spends 15 seconds handwashing a dish. In that time, the sink uses half a gallon of water. That’s why running your dishwasher with as few as eight dishes is all it takes to save water."
