Re: Is this a step backwards?
No, it's fine, because it's not a "proper files app" in the sense of the Finder. It primarily allows you to navigate your iCloud, Dropbox, etc storage and maintains local caches of that, providing applications with pipes into and out of that conceptually remote storage. It doesn't expose the native file system. You can't investigate /Applications or /Library or /usr/bin anything else. iOS-level sandboxing still applies.