Other than that, he was able to create and manipulate clouds of flame and pop that laser dragon out of his mouth with which he nearly killed Ryokugyu. It would seem that these abilities are much more difficult to recreate than the simple transformation into a (half-)dragon.
Now if it’s true that Vegapunk created such a fruitthe reason why they didn’t tell the world government is pretty obvious. If the World Government knew, they could simply mass-produce extremely powerful Devil Fruits, feed them to their soldiers, and create an unstoppable force.. This is exactly what Kaido did (or tried to do) with his crew and subordinates. He gave the most powerful the real fruits and fed the cannon fodder with the Smiles, which made them much more powerful. Now imagine that instead of a guy whose head sticks out of a chicken’s anus, you’re fighting 20 marines who can transform into dragons and shoot laser beams at you. Or why stop at the Zoans? Who says Vegapunk can’t recreate the Logias or Paramecias that Admirals use? Why even stop giving them to Marines? Objects are surely much more obedient. There are virtually no limits to this. The Marines would become truly unstoppable.
And that’s the reason Vegapunk couldn’t do it. So they lied and the World Government believed them.
They believed Vegapunk but they were definitely suspicious at the time, and that’s exactly where the key to this whole story comes in. Ryokugyu. During his fight against Momonosuke and the Red Scabbards, he makes a very interesting point.
As an Admiral who seems to be completely fine with the World Government and Celestial Dragons dominating the world, he probably knows a thing or two about the legendary (mythical) Devil Fruits circulating the world. If there were two Dragon Fruits, he and the World Government would definitely know, but his fight against Momonosuke was the first time he heard of such a thing.
Now after being kicked out of Wano he would have reported this to Akainu or the Gorosei and that obviously could only mean one thing. Vegapunk created the Devil Fruit and hid it from them. From the perspective of the World Government, this can only mean that Vegapunk’s allegiances are not what they should be.. You don’t have to be a genius to deduce that Vegapunk might also have Revolutionary Army links, given the time he spent with Kuma during the experiments. They are therefore left with only one option: send CP-0 to assassinate the world’s most dangerous scientist.