What are the advantages of having two kidneys and not just one?

Having two kidneys provides a backup system; if one kidney fails or is damaged, the other can continue to function, maintaining overall kidney health and bodily functions. Additionally, two kidneys can enhance the efficiency of waste filtration and fluid balance, allowing for better regulation of electrolytes and blood pressure. This redundancy helps ensure that vital processes, such as detoxification and waste removal, remain stable even under stress or injury.