What role do death and defeat play in the story? What point is being made by the fact that even Beowulf, this great hero, has to die?

What point is being made by the fact that even Beowulf, this great hero, has to die?

What role do death and defeat play in the story? What point is being made by the fact that even Beowulf, this great hero, has to die?
What point is being made by the fact that even Beowulf, this great hero, has to die?