I had an epiphany like Paul on the road to Damascus while thinking about the last chapter and why Laugh Tale is called that... Based on what Vegapunk said in his post-death speech, Joy Boy fought a war against the 19 countries of the world government because of their different ideologies; but this happened after he left his "treasure" since he died in that war. In my opinion, Joy Boy feared or even knew that he wouldn't make it, and that's why he decided to pass down the 3 ancient weapons to posterity, precisely to help them defeat the world government and complete his will.
So, what is at Laugh Tale? And why did Roger laugh when he saw the One Piece? And why did none of the crew decide to take possession of it? Simple, because they couldn't.
As of now, we only know that the One Piece is an enormous treasure left by Joy Boy and that those who find it learn the truth about the void century... so we can hypothesize that the One Piece, or a part of it, is something that tells a story, like a Poneglyph... "One Piece" could mean what this priceless treasure is, "A Piece", one single thing, the One Piece is a treasure composed of a single object, a Poneglyph... but not just any Poneglyph, but the most important one of all where Joy Boy wrote: his story, his will (which will be known as the will of the D) and how and why to fulfill it.
The One Piece is nothing more than a way for Joy Boy to be sure that sooner or later he would win against the world government; but not someone else, it would be him! or rather, his reincarnation... In fact, when Luffy becomes Nika, all of Joy Boy's old companions (Zunisha, Emeth) recognize him as such; so, just like "Poseidon" was reincarnated in Shirahoshi... Joy Boy was reincarnated in Luffy.
So the One Piece can only be for one person: Joy Boy, in this case Luffy; because it contains the necessary information to defeat the world government and become the new emperor of the world. But why is it only for Luffy? Because the One Piece is a "message" that Joy Boy left for himself, and in this case, it refers to Luffy since he is the only one who can become Nika.
One must "be" Joy Boy to take possession of or use the One Piece, anyone else who finds it will have made a pointless journey and that is precisely why Roger laughed, because after Oden read the Poneglyph to him, he realized that it wasn't meant for him, because he wasn't Joy Boy, and thus his journey was in vain.
So I think there won't be any problem if someone reaches the One Piece before Luffy because they won't be able to do anything with it; but it will only be when Luffy finds it, that after learning everything, his devil fruit or the will of Joy Boy residing in him will fully awaken, granting him greater strength and a new objective. Who knows, maybe the fruit will even make him relive or see some of Joy Boy's memories?
Anyway, this is my theory, let me know what you think.