The piece about sex was the part that give it a little bit of realism. All the other functions are (probably) more cheaply done by a human being (cleaning, cooking) than a robot; but sex is a whole different matter; there is diseases, "high-profile" prostitutes are very expensive and charge by the hour, expectations of a satisfactory response to stimulation, thousands of guys are socially inept or unconfirmed with their girlfriends, etc.

The operator calling her "honey" could easily be a test to see if she interacts correctly with a human even when given an sporadic nickname.