. Is the ending inevitable? Do the monster and Victor have to be destroyed in order for there to be order restored among men?

I think the ending always was inevitable given what we know about both Victor and the creature. From the beginning Victor was an unreliable narrator. His motivations for creating the creature were short sighted and unnatural. He challenges the very idea of God and creator of life. Victor's creature outwardly mirror Victors grotesque act of conception. Victor cannot take responsibility for his creation. Conversely, the creature cannot exist in a world that despises him. The creator refuses to help his creation and the two must collide until the destruction of one is achieved.