One article mentioned that dragging something to the desktop causes the app to block/freeze for several seconds. Having access is not enough on its own - it also has to be reasonably performant and not too glitchy.
The Photos app has the same kind of behaviour when dragging photos. You'd be hard pressed to select a bunch of photos/videos and drag&drop them anywhere but on a folder (typically the desktop). Even then, copying them seems to trigger an "export" process (sometimes you see a progress bar or something with that label to that effect, I can't recall right now) that takes ages. Alternatively, you can "Reveal in Finder" and copy/drag/whatever the photos/videos from there and it's instantaneous.
Even though it still triggers an export, this behavior has gotten a lot better in Mojave. Whereas previously one could only really drop images on Finder windows (Desktop counts as well) it now works in many different applications. Not quite everywhere, but at least it works most of the time and I don't just not even try it.
