To a great extent, technology has reduced the need for servants, because a lot of the work formerly done by servants has been mechanized or moved out of the house. Prepared food is less expensive, more available, and of better quality than it was in the 19th century; washers and dryers make laundry less of a full-time job than it used to be. I could expand on this ad nauseam but you get the picture. Unfortunately there are some things that simply can't be automated or bought off the shelf at the WalMart or Target. Child care requires real live human beings, and despite the advent of the Roomba you either have to clean up after yourself or hire somebody to do it. Now, labor is expensive, so for a lot of folks a nanny or au pair isn't an option, and you get child care instead. I regret that during my time on the Governor's Early Education & Child Care Advisory Committee it never occurred to me to ask the folks that were all hot for child-care subsidies how comfortable they were dishing out subsidies to the middle class for servants.
It also occurs to me that technology has enabled us to replace tutors with computer software, provided that you get the right package and filter your kids' access to the interbutt. Careful now.