Why not to provide power supply directly to PCI cards?

Directly supplying power to PCI cards can lead to several issues, including potential damage to the card from overvoltage or incorrect connections. PCI slots are designed to regulate power delivery, ensuring that components receive the appropriate voltage and current for safe operation. Additionally, bypassing the standard power supply pathway can disrupt the system's stability and could void warranties or violate safety regulations. It's best to adhere to the established power delivery methods to maintain system integrity and reliability.