Albus and Scorpius here make a conscious decision to let Cedric finish the maze, essentially sacrificing his life for the good of the wizarding world. However, it is notable that Albus does try to make a difference, even in a small way, by telling Cedric that his father loves him. He knows he can’t change the past, but also views it as important to do what he can to give Amos more comfort in the future.