The primary benefit of using microservices over monolithic architecture is enhanced scalability and flexibility. Microservices allow applications to be broken down into smaller, independent services, each responsible for specific functionalities. This modular architecture makes it easier to develop, test, and deploy changes without affecting the entire system. Additionally, microservices enable teams to work on different components simultaneously, fostering agility in development. They also facilitate the use of diverse technologies across services, optimizing performance and resource utilization, and improving overall system resilience.