Interesting points: 1. Essentially, iCloud Drive is hooking into third party apps and Apple's own apps much in the same way many developers have been linking with Dropbox and Google Drive for years. The main difference? There is no iCloud Drive app available for iOS. At least not at this point.
2. iCloud Drive is not an all-in-one replacement for apps like Dropbox and Google Drive where iOS is concerned, at least not yet. If you want to organize and access files in one single app on the go from your iPhone or iPad, you'll still need to use a service like Dropbox or Google Drive.