One Piece Mermaid Island Why did Li Xia predict that Luffy would destroy Mermaid Island?

Hehe, let me sum it up. Anyone who has seen the story of Mermaid Island in One Piece will know that the mother of the Mermaid Princess White Star hopes that humans and fishermen can live in peace * * * and until now, there are still things like signatures, which indicates that one day humans and fishermen will live in peace * * * on a piece of land. Moreover, Li Xia's prediction can't be wrong, and Oda won't find other excuses, saying that the destruction of Luffy must be his destruction. Now Luffy obviously doesn't have this strength, so he will mention the white star in future stories (because his mother said that someone can control the power of the white star) (it must be Luffy). When Luffy is strong, it will help Mother White Star to achieve peace between human beings and fishermen. When fishermen and human beings live under the same sky, fisherman's island is worthless, or some people make trouble or are unwilling to go ashore (some incidents may happen). At this time, Luffy naturally destroyed Fisherman's Island in order to make human beings and fishermen peaceful (there is no doubt about Luffy's character).