The proposed railway would connect Brazil to a new port on Peru’s Pacific coast, creating a trade route with China that would allow it avoid routes going through the Panama Canal and around the southern tip of South America.
Rail is pretty hard to build and operate through the Andes and can’t reach the scale of sea freight, which could be achieved through a Nicaragua canal, but fine, it is not meant to compete with the Panama canal, so no need to build another canal.
Because a railroad is much cheaper and easier to build than a canal through mountains and jungles.
Rail is pretty hard to build and operate through the Andes and can’t reach the scale of sea freight, which could be achieved through a Nicaragua canal, but fine, it is not meant to compete with the Panama canal, so no need to build another canal.