Few things you touch outside the bathroom will be as dirty as the sink faucet. But even so, I don't always wash my hands this way. I do in sensitive situations, though -- at the office where someone's always sick, when I'm preparing food, or when wounds / orifices are involved.
That's why I prefaced with "If your goal is to get clean." Sometimes it's just to satisfy a taboo. That's okay.
If your goal is to actually clean your hands, then it's not a waste. Proper hand-washing requires not touching anything dirty after you've cleaned up. And how did you turn the faucet on? With your dirty hands. So, wash, dry with a paper towel, turn faucet off with paper towel.
First chart's huge dropoff is an artifact of choosing a yrange of 21-41 instead of 0-100. It's a common deficit of charts created under motivated cognition.
That's why I prefaced with "If your goal is to get clean." Sometimes it's just to satisfy a taboo. That's okay.