What are the reasons for avoiding performing heavy tasks on the main thread of the application?

In Android, the main thread (UI thread) is responsible for rendering the interface and handling user events. If heavy tasks, such as long computations or input/output operations, are performed on this thread, it will lead to:

• UI freezing (ANR — Application Not Responding).
• Slower response to user actions.
• Poor user experience.

Therefore, heavy tasks should be executed in a background thread, using mechanisms such as AsyncTask, HandlerThread, Coroutines, or other asynchronous programming techniques.