A Funny Thing Happened on the Way to the Forum is an interesting musical, in that it is a musical that is markedly different from most of Sondheim's other works. "Everybody Ought to Have a Maid" is a good example of a silly song that Sondheim wrote without any particular reason, other than for the audience's amusement. Though the song does add humor, it is not necessary to the musical, overall, and it would likely be just as good without it. Its melody is memorable enough, but it does not contain any truly revolutionary musical compositions like some other Sondheim musicals do.
Of course, it must be taken into account that Sondheim was still discovering his style of writing and composing when he wrote such musicals as this and Anyone Can