The primary advantage of using microservices architecture is its ability to enhance application scalability and flexibility by decomposing applications into smaller, independent services. Each microservice can be developed, deployed, and maintained autonomously, allowing teams to innovate and iterate rapidly. This architectural approach improves fault isolation, as issues in one service do not affect the overall system. Additionally, microservices facilitate the use of diverse technologies and programming languages, thereby optimizing resources and accelerating time-to-market. Overall, this structure supports agile development practices and enables organizations to respond more swiftly to market changes.