I'm guessing the author is young and this is their first time through all of this (like most of the posts on HN)... As with all things in computing, trends are

I'm guessing the author is young and this is their first time through all of this (like most of the posts on HN)... As with all things in computing, trends are cyclical. First you have big central systems, then distributed systems, then big central ones again. Same thing goes for UI metaphors. First of all the filesystem is a required part of any OS, and the OS could not exist without it, so it will never go away. The GUI on top may or may not choose to present it. The Newton, original Palm OS, and now IOS take the route of sandboxing the files and the app into the same place, and the user just sees everything as part of that app. Plenty of other OSes don't do this. Sandboxing has its obvious set of problems, such as the inability to use different apps to access the same data. There might be APIs that allow for certain types of access, but that just not the same thing as allowing anyone to access any type of file.