Mocks for databases are often fragile and difficult to maintain, requiring precise control over complex database behavior. They can lead to brittle tests that are tightly coupled to specific mock implementations, making them prone to maintenance issues and debugging challenges. In contrast, branching provides a more reliable and efficient approach by creating isolated copies of the actual database, allowing developers to test with real data and behavior while minimizing overhead. This approach enables faster development cycles, reduced resource costs, and improved reliability, ultimately leading to better system performance and user experience.