After giving it some thought, I think The One Piece isn’t Bink’s Sake, nor is it a sake recipe. Yes, the story uses sake as a symbol of brotherhood, and Gol D. Roger treasured his crew and his freedom above all else, but that doesn’t explain why the moment Roger finds The One Piece he bursts into laughter.
There’re many reasons why somebody may laugh: by being surprised by something unexpected, being overwhelmed by something intense and attempting to process it, or reacting with great amusement to what the one laughing saw. It is a tool for processing life’s events and making sense of a world that doesn’t always make sense.
Roger spent the last year of his life finding The One Piece, despite him being sick/poisoned/having an incurable disease. He gave it his all to find this mythical thing… only to laugh his guts out the moment he finds it? He wasn’t mad, he wasn’t sad; all accounts showed that he was actually full of joy, as if all his hard work and effort was not in vain despite nearly killing himself getting there. There was no despair that day, nor was there frustration.
Gol D. Roger was satisfied, but delightfully surprised, by what he saw. The journey was worth it for him, so worth that he sent the entire world looking for The One Piece just like he nearly killed himself to find it. Depending on translation, Gol D. Roger said he left “his treasure” there at LaughTale. The things he treasured? His crew and his freedom. He didn’t leave his crew there, so he could only have left his freedom.
Roger’s words show that The One Piece wasn’t taken from LaughTale (else he would have told everyone he had taken it), so it’s not an object or thing that can be taken easily from the island. Sure there are records from the Void Century on LaughTale, but that wasn’t what caused Roger and his crew to immediately burst into laughter upon witnessing it; there would have been time needed to decipher the records. It was something they recognized immediately upon seeing it, and were happy that they found it.
It must be something that protects the freedom and brotherhood of humanity, not just a symbol of it. It must be something that makes the journey “worth it” to somebody who just wants to do whatever they want with the people they care about. It is an instrument of freedom.
A sake recipe, or a mountain of sake barrels, can’t do that by itself. Yeah a giant party with a mountain of sake is fun, but the party has to end eventually. However, The One Piece is something that takes time to mature which is why Roger doesn’t reveal what The One Piece is to the world; it wasn’t ready.
This leads to my theory:
The One Piece is a World Tree of Devil Fruits, or a grove of Devil Fruit Trees. They are immature and growing, and are about to mature and be released upon the world.
What could cause the World government to quake in their boots at what Roger found? A power that cannot be suppressed or controlled by them. What would break their hold on the world? Devil fruits, because the abilities and powers they grant give normal people extraordinary abilities, abilities powerful enough to defy the World government’s authority.
Why have Devil Fruits been associated with pirates and those who fight the pirates? Because great power tempts the wielder to use that power. They would fight back at anything that restricts them from exercising that power, which puts them in opposition to the world government. So what happens if millions of Devil Fruits were to be unleashed upon the world? The most ridiculous war the world has ever seen!
There was once a World Tree of Devil Fruits much bigger than the current one (or ones) on LaughTale. It originated elsewhere in the world and grew fruits at regular intervals, and threatened the world government by granting thousands of people ridiculous and fantastical powers. However, the World government desired peace and stability. They wanted a world without fantastical and ridiculous powers granted at a moment’s notice to completely random people and causing chaos as a result.
Thus, the reason they are even called “Devil Fruits” could be that the World government tried to disrespect and defame the users of the fruits and the powers they possessed, portraying them as “evil” and the opposite of “good”, when in reality all they do is give people power they otherwise would not have.
JoyBoy guarded The World Tree, but was betrayed by his close friend Im who was swayed by the allure of total control over the entire world that the world government promised he could have. Im led the burning of the original World Tree, forcing JoyBoy to flee with a transplant or seeds of The World Tree.
While fleeing, JoyBoy left the Poneglyphs as a recording of his failure to keep the Devil Fruits growing and being unable to give everyone in the world a Devil Fruit. However, he leaves his Will behind and his desire to see the world free of the shackles Im has put the world under through Im‘s iron-fisted command of the World government.
The Void Century was a crackdown on Devil Fruit users that almost resulted in Devil Fruits and the knowledge of them being wiped from the world. However, The Will of D could not be stopped forever. Devil Fruits started to slip through the cracks of the world government’s clutches despite Im’s desperate efforts, and the Devil Fruit Trees growing on LaughTale were slowly maturing after being planted/transplanted by JoyBoy a thousand years ago, waiting for their chance to be unleashed upon an unsuspecting world and finishing what they started.
The only way the entire world could be freed from Im’s ambitions is if EVERYONE IN THE ENTIRE WORLD SIMULTANEOUSLY RECEIVES BRAND NEW DEVIL FRUITS WITH RIDICULOUS AND FANTASTICAL POWERS NOBODY HAD SEEN BEFORE.
Imagine Gol D. Roger, coming upon this island, and realizing the transformative power of the Devil Fruits growing there. Imagine the wheels turning in his head, the import of which gets pieced together in his consciousness as he realizes the ridiculous world-spanning conflict about to be unleashed and the resulting collapse of the World government.
What else could he do, but laugh his guts out?
Devil Fruits are rare throughout the world of One Piece, and have a will of their own, meaning having a Devil Fruit elevated you above those who didn’t have one because of the power boost it could give you, regardless of any haki training or talent you may or may not possess. The entire world population gaining Devil Fruits would evaporate such elitist distinctions in a HEARTBEAT.
Now, everyone would be on the same initial footing, with haki training and talent being the only division in power left, and as powerful as haki is it can only be achieved, not gifted. Even talented users must do SOME haki training before their talents can blossom, and the more they train the more powerful they become.
With the baseline leveled out, the World government would be powerless to stop the citizens from flaunting their newly-gained powers, but not without trying. There would be a world-spanning battle that would be the entire world’s populace facing off against a beleaguered and increasingly desperate World government.
Of course, the Devil Fruits are still immature when Roger finds them, which is why he doesn’t take them. They are still growing on the trees, not yet ready for the harvest. Once the fruits are mature and ready… ALL THEY NEED IS SOMEBODY TO PLUCK THEM FROM THE TREE, freeing the fruits and allowing them to appear wherever the fruits want to in the world.
Who do you think should be the one to pluck the mature Devil Fruits from the tree? The chosen wielder of JoyBoy’s Devil Fruit, The Sun God Nika, the one who is the spiritual descendant of the original tree’s guardian JoyBoy: Monkey D. Luffy.
By unleashing a massive harvest of Devil Fruits, Luffy would effectively turn the entire world on its head, causing tremendous chaos within and without the world government and leaving them powerless to tame the resulting conflict. The World government tried tremendously to control and subdue the Devil Fruits for hundreds of years, only to be thwarted by their ridiculous powers and abilities, which could even animate solid objects into living things if the Devil Fruits so desired.
The fake Smile Fruits the world government created are missing the ridiculous powers normal Devil Fruits could grant to their wielders, leaving them incomplete husks unable to feel “normal” because they are unnatural imitations, granting enslavement and subjugation instead of freedom.
The resulting conflict born from everyone getting their own personal Devil Fruit would create a “new normal”, one that is distinguished by what people accomplish with their ridiculous and unpredictable powers. This would force everyone to respect the unpredictable power and ability of everyone else, because you never know what strategies they could unleash because their new powers allow for unconventional tactics that could not be fought against.
This respect for the other person’s strength leads to a spirit of cooperation and brotherhood, as people unite over their shared respect for the power and talent the other person holds. When everyone has a Devil Fruit, fighting becomes VERY dicey and complicated, especially upon first contact. Thus, most would only fight if they felt that they had to fight.
This will, in time (and with MUCH conflict), unite the world under one common shared understanding and one common heritage: the Will of D, or the Will of the Devil Fruits. The Will is simple: to NEVER leave a person powerless. To give power to those that have none, to give hope to the hopeless, to aid the helpless and TO GIVE EVERY SENTIENT CREATURE A FIGHTING CHANCE TO SURVIVE AND THRIVE.
Theory by Plus_Candidate_8011 (https://www.reddit.com/user/Plus_Candidate_8011)