Exactly that. We started off Wano with "we must open the borders" and ended Wano with "borders are not to be opened" so we as reader's are exactly in the same position as we were 5 years ago where we learned nothing, where subplots are still unresolved, and new subplots keep getting added. Completely pointless arc.
You are just upset it hasnt happened, without realizing the entire focal point of Wano was first and foremost about Kaido. Opening the borders has to do with endgame relevancy. This isnt rocket science.