Why does Harry Potter say that Harry is the savior?

At first, the wizarding world didn't know that Harry was protected by Harry's mother's protective spell, but only knew that Voldemort couldn't kill Harry when he was a baby, and he didn't take advantage of Harry after meeting him many times, so he thought Harry was the savior, because he was the only one who almost killed Voldemort, but Dumbledore couldn't, especially in the sixth episode, Dumbledore died. As for the real reason, the prediction in the fifth episode has been explained. Voldemort himself chose Harry instead of Neville as his enemy, and only one of them could survive. Evil cannot triumph over justice. Rowling can't let Voldemort rule the wizarding world, and Harry becomes the savior.