The problem that this feature will solve:
Variables as far as I can tell, only exist as global values - so I can make a box with width/height/depth, but any duplicates of that object will all match the same values. I can change values and all boxes will change. This is a valid use case, however by adding object specific variables, I could duplicate an object, modify its variables in isolation, allowing rapid creation of multiple variations of complex objects.
Brief description of the outcomes that you expect from this feature:
When creating a variable, you would have the option to assign it to the selected object or make it global
When copying an object, the variables will also be copied, references would be updated to the new local variable instances, these will not be linked to the previous variables/object.
Any global variables used remain global and unchanged in operation
What can’t you achieve without this feature?
Obvious use case for this is stuff like gridfinity - I might want to make multiple sizes of a box and arrange to fill a container - the workaround is of course to save a new file for each item, but seems like a chore.