Repetition can be a useful dramatic or comedic device.
Lots of comedies rely on the same joke being repeated over and over. The audience comes to expect it, and this expectation can add to the humor rather than subtract from it. The play "Funny Thing Happened on the Way to the Forum" comes to mind. Early in the play a character is told by a fortune teller that he must run around the seven hills of Rome seven times. And then throughout the play, totally unrelated things are happening, and suddenly this guy runs across the stage shouting "one!", then "two!" etc. The characters all stop and watch him run by, and the audience laughs at the interruption.
In drama, repetition sets up an expectation. It sets up anticipation. The audience KNOWS that that person wandering through the woods will be attacked by the psychotic killer, or that the heroine's latest boyfriend will turn out to be a jerk just like all the others, or whatever. Surprise can be effective, but so can anticipation.
Of course if it's exactly the same every time -- if you just have the same scene played out ten times -- that's going to be boring. There has to be some variation. So the audience knows that X will happen again, but they still wonder, how will it play out THIS time?
You might even break the pattern for a surprise ending. Like many things in writing, if it's done well, it can be an effective surprise. If done poorly, it can be a disappointment. "But wait, isn't he going to do X?" Or worse still, a gimmick. "Oh, he set us up to think X was going to happen, and then he did Y."