“The Premier Ball (プレミアボール Premier Ball) was created for a special event. According to the official Pokémon Colosseum game guide, it has the same catch rate as a regular Poké Ball, but “it looks cooler”. It has basically no other purpose except for giving an extra ball when buying 10 of them, so it’s a free Poké Ball but it has a different design.”
So its actually quite clever. You cant use poké balls, great balls or ultra balls for raids, cause its confusing. There is alot of other balls in existence in the games, but they all serve a special purpose. Since the premier ball has the same stats a pokéball has, its the best choice for raids.