That's probably why I mentioned libraries..
With a traditional OS, you tell the OS where your files are by navigating through a hierarchical list of files and folders. This is not an advanced feature.
With an advanced OS, the OS knows where your files are and brings them up when you need them. iOS has elements of this but it's not all the way there, which is why some people want a traditional file system. My point is that adding a traditional file system would not be an advancement (it's an old/dated concept), although in some cases right now it may be an improvement.
iOS maintains libraries for certain items, like photos which are accessible from any app without you telling the app where to find them. Windows 7 can create libraries from multiple folders. The idea behind a Library is that the user doesn't need to know where the file is, the OS just needs to be able to bring it up for you when you want it.
With a properly set up video library, you wouldn't need to store videos in the same place, the OS would simply know where they all were (for instance, in other app folders) and let you access them from wherever you wanted.
The traditional, visible and hierarchical file system is how we are accustomed to accessing our files, but it's certainly not the most advanced.