Why is Mrs. Danvers role throughout Rebecca so significant?

Without Mrs. Danvers, there would be no mystery to this
novel because it is she who keeps Rebecca's ghost alive. We learn the truth about
Rebecca and how evil she was by the end of the novel and we also learn that Maxim came
to despise her, and that he was the one that killed her. So, Rebecca's memory would not
even come into play if it had not been for Mrs. Danvers. If not for Mrs. Danvers, the
new Mrs. DeWinter would not be so insecure, would not think that her husband is still in
love with Rebecca. Mrs. Danvers moves the gothic nature of the novel forward by trying
to get rid of Mrs. DeWinter. She dresses her in Rebecca's clothes, she tries to convince
her to commit suicide, etc. If it were not for her, Maxim would have brought his new
wife home and they would have learned to build their life together, in spite of his past
tragedy with his first wife, Rebecca. In Mrs. Danvers, we have a living evil, whereas
Rebecca's evil is part of the past. Mrs. Danvers keeps Rebecca's memory and her ghost
alive.