Coz Oda is bloody lazy. He only writes what he wants to write and will make characters disappear without any bloody explanation. Honestly Jimbe is so fcking finished this arc as a result of it.
Anyways on Sanji v Kilinbum it’s pretty obvious that Zaza is going to be the main obstacle of this fight. It’s already being established as Bellingham’s greatest creation that even he doesn’t have full control over which imo is massive red flag that will most likely lead to Kilinbum’s demise.
But yh, whatever challenge is presented towards Sanji this fight will be Zaza relate imo. It’s interesting though that Oda’s pitting Sanji up a against a feminine looking monster and forcing him to take action in a situation where the lives of Elbaphans are on the line

So PL aside from a story telling perspective it could be interesting. Also find it interesting that this so called Zaza is capable of creating floods given Sanji is said to be the best swimmer amongst the strawhats.