Faster, because real cashiers have strategies like item x 6, and the authority/passcode to use them. And because they do it all day they have muscle memory working for them. We look at a head of lettuce and my brain says "romaine" or "frisee" but their brain says"5046" or whatever the right code is. Or rather it tells their fingers to type the code without interrupting the more important things they're actually thinking.