[throw0101a]

> Is it about water use? What if you don’t run the water while you soap your dishes and only rinse them in a rinse tub?

Yes: if your dishwasher has the Energy Star rating then it must use ≤15L of water using the normal cycle per the EPA. This is half the volume of a small sink and a one-third or less of larger ones.

Most people run the water. In the US the average flow rate of a kitchen faucet is 8 L/min (2.2 gpm), so you can quickly use up 15L even just rinsing.

[bluGill]

Most people use as much water rinsing their dishes to almost clean before putting them in the dishwasher.

[throwaway0a5e]

Very few people are running the faucet anywhere near full blast when dish-washing.

My faucet is very slow, about ~1gpm (I timed it once upon a time because I wanted to be able to put a number to how slow it is). When hand washing I run at maybe 1/4 or less of that. Everyone else in my household runs it at less.