In Chapter 1041 the CP0 receives an order from the Five Elders. Monkey D. Luffy shall be eliminated immediately.
This led many people to believe it’s due to Luffy having a special devil fruit that once belonged to Joy Boy.
Now, here is a fact that denies this argument: If Luffy has the devil fruit of the probably most important enemy of the World Government in whole history, why didn’t they act earlier? Luffy used this fruit in Enies Lobby, right before the eyes of the CP9 and no one cared about it. Luffy used his powers in front of the whole Navy and no one cared about it. Neither did the Admirals nor did Sengoku. While Luffy was weak back then it would’ve been an easy task to kill him, but the Gorosei didn’t seem to care about it.
So with Luffy having the Gomu Gomu no Mi devil fruit since more than 2 years, having used it right in front of the World Government and Navy now they care about it? This would be a plothole, not a little one, not one you could ignore this easily. Now here comes my theory: Luffy should not be killed because he has a special devil fruit, but because he is Joy Boy.
How do I come to this conclusion?
Well, whatever the World Government noticed in this battle, must be something they couldn’t see in former battles, indicating that Luffy now has something that cannot be ignored anymore. His ability to even turn enemies into his allies, the ability of Joy Boy. Why is this ability connected with Joy Boy? Because the insane amount of willpower, the will to survive and enjoy life by its fullest is spreading like a disease among everyone around Luffy. Luffy completely turned the tides of this battle (also thanks to Chopper and Tama). He made everyone believe that he has a chance of winning.
At the start of the battle against Kaido and Big Mom Kid and Law were rather worried about losing, not believing they have much of a chance.
Now, in Chapter 1038, they seem to have changed their attidude with Kid stating that he would die only for Big Mom to not be able to reach the roof and to interfere in Luffy’s fight.
This ability of Luffy is what scares the World Government, not his devil fruit!