The purpose of having different characters in Banksters is to provide players with different abilities that are linked to each character class. The six different classes (Trader, Investor, Shark, Whale, Illuminati, or Reptilian) offer players unique sets of abilities that can be used to increase their chances of winning in Investment Runs, attack other players, or defend against attacks from others.  These abilities can be upgraded as players progress through the game and level up their Banksters. Having different characters adds an extra layer of depth and strategy to the game, as players must carefully manage their resources and abilities to advance and succeed.