My family does not, so far as I can tell, use a different number of dishes because of the presence of a dishwasher. The kids almost never wash(ed) up, so it makes/made no difference to them for example. And I loathe washing up, but I always use as few dishes etc as I reasonably can simply from a sustainability point of view. And I ensure that the dishwasher is as full as reasonably possible before being run, and run at the best time from a carbon/cost point of view.