Collections are useful to organize and instance objects, but IMHO the outliner needs some implementations.
The “Scenes” view, is my favourite because it’s the only one that shows object’s hierarchy and collections instances… but lacks an important feature: with old Layers sytem, i can activate/deactivate layers and set the outliner to show only “visible layers”. It’s useful because in that way i can hide certain objects (layers) from the vieport and also n the “Objects” list of the outliner.
With collections, i can hide a collection, but the “objects” list always shows all scene objects!
Imagine to have hundred of objects, and you must continuously scroll the list to find the one you need!
I think it’s better to have an option to hide the object from the list, when you hide the related scene collection.