Here's why:
* Evolution Items are Single Use: Moon Stones, like other evolution items (Fire Stones, Thunder Stones, etc.), are designed to be used only once. Once used to evolve a Pokemon, the item is consumed and cannot be used again.
* Trading and Finding: You can obtain more Moon Stones through various methods:
* Trading: Other players may have extra Moon Stones they are willing to trade.
* Finding: Some Moon Stones can be found in the wild, typically in specific locations or as rare drops.
* Events: Some events might offer Moon Stones as rewards.
Remember that the specific methods for obtaining Moon Stones vary between different Pokemon games.