* It's a win condition, not a power card: Exodia's strength lies in its ability to win the game automatically when all five pieces are in your hand. It doesn't have any attack or defense stats, nor does it directly affect the opponent.
* It's reliant on drawing: Exodia's power is entirely dependent on you drawing all five pieces. If you don't, it's essentially useless.
* It can be countered: Many cards in Yu-Gi-Oh! can prevent you from drawing or search your deck, thus negating Exodia's effect.
Other cards can be considered more powerful due to their versatility and ability to directly affect the game:
* Cards with high attack power and special effects: "The Winged Dragon of Ra," "Blue-Eyes Ultimate Dragon," and "Cyber Dragon Infinity" are some examples of cards that can directly attack your opponent's Life Points and have powerful abilities.
* Cards that control the field: Cards like "Dark Magician" and "Chaos Emperor Dragon - Envoy of the End" can manipulate the field and make it difficult for your opponent to play their cards.
Therefore, while Exodia is iconic and a powerful win condition, it's not the "most powerful" card in Yu-Gi-Oh! due to its dependence on drawing and susceptibility to counters.