Neither do I. Not in my devices.
Now a common file bucket so I can skip all this 'import from iTunes' and 'export to iTunes' nonsense for file sharing. Or having five copies of the same file so I can use it in different programs. Okay that I can go for
Unless Apple gives the file app direct root access or some short of privileges, you will still ended up with five copies of same file for different apps. All app should have directly access to the file app and have the ability to save to the disk. Otherwise, it is pretty much meaningless