In short, it has nowhere near the level of functionality that it should do. Apple clearly want to compete with established services like Dropbox and OneDrive, but rather than emulating the simplicity of file-folder hierarchies and similar management on mobile devices, they've built upon the convoluted system of apps having 'containers'. This makes no sense at all - if you turn iCloud Drive ON, why should you have deal with these containers and their aliases?
What's worse is that Apple expect people to use their service on a day-to-day basis for work. Unless they out the file management on iOS, they'll continue to trail behind.
My sentiments exactly. Well said buddy!