While CLEAN architecture may seem complex, it offers clear benefits, especially for larger Flutter projects. Its layered approach ensures better scalability, maintainability, and testability as your app grows. Though feature-first can work well for small apps, CLEAN architecture helps avoid messy dependencies in larger projects. It's mainstream because it solves real-world problems, not just due to trends. Ultimately, it's about choosing the right approach for your project's needs. Both have their place, depending on the scale and complexity.