Why are layers significant in Unity?

Layers are significant in Unity primarily because they enable categorization and filtering of GameObjects. By assigning GameObjects to specific layers, developers can manage how they interact with other GameObjects and which objects can be seen by certain cameras or affected by certain physics operations. This is particularly useful in complex scenes where a game may contain numerous objects, helping to optimize performance and organization.

For example, by using layers, one can set up specific rendering settings for objects, preventing unwanted interactions, like making certain objects invisible to the camera or exempting them from certain physics calculations. This organization enhances both performance and clarity in game design, ensuring that developers can easily manage large numbers of assets without confusion.