If you are referring to a system backup on an external drive then the answer is obvious. If you are referring to advise you received to create a drive to organize your documents folder, no it would not solve your overused Documents folder problem. Music and Videos folders already exist so move those from Documents to their respective folders. A Saved Games folder already exists too in Windows 10 but I can not tell you how to access it besides a folder search. If your documents folder is still cluttered, delete any unnecessary items.
I know you do not want to create new folders but if you did they could be stored inside the documents folder which is how most folks handle the problem.
