One thing I have noticed is that the way it is broken down by state switch in the U.S. is extremely helpful.
But I agree with Philip that just having {{Unsourced}} is generally useless, and can be worse if it just gets in the way. So I narrow them down as tightly as possible with a state switch, even if the state is pretty much of an educated guess.
So then the profile does end up in a category that is workable by the Sourcerers who have particular expertise with the resources of their particular state of interest.
On the default with new creations that are sourceless, it does need to be the general {{Unsourced}}. But in general, people should probably not be manually adding that template in the absence of any appropriate location switch.
Also, some people tend to over-apply it, on profiles that do have something under the source header, or in the bio that can be construed as a source, but that could be a better or more complete source instead. Too much of that sort of thing just makes for clutter, as with the tendency toward over-categorization in general as well.
