There are two arcs in one piece that are specifically about treasure hunting. The Island of Rare Animals and Skypeia. Both are the only real treasure hunts in OP, and likely the arcs with the most potential parallelism to the act of finding one piece and the nature of the treasure in itself.
Upon further examination, both of these arcs have a lot in common, in terms of the identity of the treasure itself.
In Gaimon's treasure, the straw hats help gaimon look for his fabled treasure
In Skypeia, the straw hats and previously Noland search for the fabled city of gold
And in both cases, the intended treasure is always missing. Gaimon's treasure is a treasure that has already been taken by somebody else. The treasure chests are empty. When Noland returns to shadora, he finds absolutely nothing there. The knock up stream displaced it entirely. When the Straw Hats arrive, the gold city of shandora has already been picked clean of most of its gold by enel. When robin discovers it, most of what is left is stone and jungle.
These arcs may intend to establish the idea that the One Piece may not be at laugh tale when either
1) the crew arrives there (The one piece being in someone else's hands is an easy way to justify the final war that is being foreshadowed)
2) Roger arrived there (why he laughed, why he didnt act on the information he learned, why he mentioned he wished he lived in joyboy's era, and why he kick-started the great age of piracy to pass the torch to someone else)
3) Both arrived there (it was always somewhere else than raftel in the first place)
I don't mean to say that there wont be anything meaningful for the straw hats at raftel. In both of the arcs previously discussed, the real treasure still present is really something else much more understated. Specifically, something that the rightful owners of the treasure swear to protect. Gaimon's true treasure is the rare animals at his island. Shandora's true treasure is the poneglyph that the warriors swore they would protect. There will almost certainly be some form of consolation prize or greater treasure.
Upon further examination, both of these arcs have a lot in common, in terms of the identity of the treasure itself.
In Gaimon's treasure, the straw hats help gaimon look for his fabled treasure
In Skypeia, the straw hats and previously Noland search for the fabled city of gold
And in both cases, the intended treasure is always missing. Gaimon's treasure is a treasure that has already been taken by somebody else. The treasure chests are empty. When Noland returns to shadora, he finds absolutely nothing there. The knock up stream displaced it entirely. When the Straw Hats arrive, the gold city of shandora has already been picked clean of most of its gold by enel. When robin discovers it, most of what is left is stone and jungle.
These arcs may intend to establish the idea that the One Piece may not be at laugh tale when either
1) the crew arrives there (The one piece being in someone else's hands is an easy way to justify the final war that is being foreshadowed)
2) Roger arrived there (why he laughed, why he didnt act on the information he learned, why he mentioned he wished he lived in joyboy's era, and why he kick-started the great age of piracy to pass the torch to someone else)
3) Both arrived there (it was always somewhere else than raftel in the first place)
I don't mean to say that there wont be anything meaningful for the straw hats at raftel. In both of the arcs previously discussed, the real treasure still present is really something else much more understated. Specifically, something that the rightful owners of the treasure swear to protect. Gaimon's true treasure is the rare animals at his island. Shandora's true treasure is the poneglyph that the warriors swore they would protect. There will almost certainly be some form of consolation prize or greater treasure.