Hello Ilozen,
Layers give you extra organizational functions.
From docs: For example, you might be working on a building that has multiple [floors] but is comprised of many modular parts. By assigning each floor to a layer, you can hide each of the floors you are not working on making the top view much more manageable.
So in the outliner, you might have a folder ‘lights’ with all the lights from all the floors, but then you could have specific lights per layer.
I’d also consider working with Levels if it makes sense for the project. (Discreet areas)
I noticed that I cannot right click on the ‘Layers’ panel when using World Partition. I think the expectation here is that you’d use the new “Data Layers” system (Window → World Partition → Data Layers Outliner)
Hope that helps!