Feature flags, while useful, are not ideal for managing API versioning, particularly when dealing with significant upgrades like moving from version 1 to version 2. In such scenarios, maintaining both versions becomes necessary, and using feature flags to control different versions can lead to complicated, unmaintainable code. Instead, creating a separate microservice for the new version allows for cleaner code management and avoids dependencies on the older version, though this approach requires discipline in maintaining microservices. The Split Feature Data Platform provides a solution by allowing developers to manage feature flags effectively, enabling faster and safer deployments without compromising existing functionality, and supports feature experiments like A/B testing to optimize development processes.