I am not very experienced with 2d games and different graphical techniques for them, but for 3d games you can get away with vertex/fragment shaders most of the time. For what kind of effects would I need to change graphical pipeline? Maybe custom 2d lighting with shadows + some sort of post processing?
Post processing is a good example of when you’d like to add additional steps to your rendering pipeline. Shadows and lighting is another. Mixing of 2d sprites and 3d models.
Another good example of changing it is just if you would like to add something above gui. Previously there was no particles nor spine in gui and therefor you constantly was mixing with that in render script. Now you only might want to add a gameobject/mesh above gui.
Also as I’m not using any of the great camera libs from community I usually fix my render view in there (lock width, lock height, camera zoom etc)