The Nika Fruit Is The Key To The One Piece
Based on the recent chapters and context clues we have in the story, the One Piece itself is probably the key to changing the world somehow. However, there are clear implications that suggest that the treasure falling onto the wrong hands may be catastrophic.
If Joy Boy knew this, I think he would put in place measures to make sure only the correct person could do it and that correct person is the person who is capable of awakening the Nika fruit.
I believe that the Roger Pirates were able to go to Laugh Tale and learn the truth. They learned about what they need to do, but they weren’t able to access to utilize whatever the treasure is because if they could, I don’t understand why they would not.
I think there are several things that hint to this being the case.
*Theory by MonkeyDlurker