"...this is stuff in folders or on the desktop." Sure...I never mess with system files anyway. EVERYTHING I do is from one folder to another: I 'almost' never put an actual file on my desktop.

But, in Windows, the desktop is treated 'almost' as another folder....as in this image from another file manager I play with.
The right hand window IS the desktop, although all I have there is shortcuts.

Now, I just saved that image of my folders TO my desktop, then I dragged it FROM the actual desktop to a folder listed in the left window. It appeared in the folder and disappeared from the desktop. (I think that's the first time I have done that in years. I always download files from the WWW to some specific folder, whether it be called 'temp' or 'downloads' or 'Bill's pics')
If I don't use the desktop for temporary storage (and I never do), I can drag or 'click' or copy with F5 or move with F6 from within the file manager with no problems.

I think I will explore Windows Explorer to see if I can find a way to change some default for what dragging does. It's fascinating to see how this actually works and how many different ways there are for people to work with stuff.