Why is Controller responsibilities important in Laravel applications, and what problem does it solve for developers?

Why is Controller responsibilities important in Laravel applications, and what problem does it solve for developers? The key reason to understand controller responsibilities is that Laravel applications are usually composed of several layers that must work together predictably. Controllers should coordinate the HTTP request rather than becoming a dumping ground for every business rule. Ignoring that boundary can lead to duplicated logic, poor security, unnecessary database work, or code that is difficult to test. Why it matters in practice: Controllers group related request-handling logic and commonly coordinate validation, services, models, redirects, views and API responses. The specific focus here is controller responsibilities: Controllers should coordinate the HTTP request rather than becoming a dumping ground for every business rule. This question is designed to test not only terminology, but also how the concept fits into Laravel's request, application, database, security, or deployment workflow.