I assume most Blender users, dont work with huge files.
But those who use it professionally making commercials / movies, working with large models might see the bennefit of this. If collections could have animatable exclusion this would allow for faster prefiew and faster rendering.
For scenes where objects are not visible currently in camera view.
For example the trees and mountains behind you far away, the house at the other side of the hill or the cargo of a truck, the driver of the truck when vieweing from behind, or the blood vessels in a medical animation who needs to show first the person and later the veins.