Here's why:
* Gameplay Focus: Budokai 3 focuses on battling and unlocking characters, not on traditional Dragon Ball story elements.
* Story Mode: The game has a story mode that follows the anime storyline, but collecting Dragon Balls isn't a crucial part of it.
* Dragon Ball Collection: You can collect Dragon Balls in the game, but they are primarily used for unlocking special items like "Z-Souls" which offer stat boosts to your characters.
Therefore, gathering all the Dragon Balls in Budokai 3 won't result in summoning Shenron or granting any specific wishes. It primarily serves as a way to unlock unique rewards and enhance your gameplay experience.