Why could the play have ended after the 4th Act?

he surface it might seem that the play could have ended here. At the end of Act four, not only do the two lovers get married but there has been a happy resolution to the conflict. The final act challenges the audience as to the nature of fantasy and reality.Shakespeare is trying to drive home a point about theater; he wants to make it very clear that the ending to this play could just as easily have been tragedy, not comedy. We would also have missed Puck's famous "If we shadows have offended" speech. Please take a look at the source link below. You can find this in greater detail at the GradeSaver site.