Files for iOS and iPadOS eliminate information lodged in the folder.
While the File app for iOS and iPadOS gives you access to explore iCloud Drive, some local storage, and third-party cloud storage, it eliminates important pieces of information that have been a useful part of file navigation from the start of computing: storage occupied by folders ( or directory) and everything that is lodged in it. This makes it effectively impossible to know what occupies your iCloud storage if you need to delete it to make room for other files.
Launch the Files application and you can see for yourself. Tap iCloud Drive and any file at the top level is registered with the name, date, and size. Folders, however, only tell you how many items they contain – and that is only at the top level, not including layers of nested folder items in. iCloud.com is even worse. You must click the “i” info button on the file to see its size.
The way to overcome this is to use macOS. iCloud Drive on macOS is subject to the same Finder control type as other folders. When viewing a folder, select Finder> Preferences and check the Calculate All Sizes box near the bottom. In the Size column next to the folder, the entire number of nests appears; if you have lots of files on iCloud Drive (or in any folder), it might take time.
The iCloud Drive Finder folder can be set by the Get Info dialog (enter) to display the total nested storage of any folder.
You can use this total to help find and get rid of unwanted files. Apple can bring Files for iOS and iPadOS and iCloud Drive to iCloud.com until the mid-20th century by adding an easier way to see this total.
If you don’t have a Mac linked to your iCloud Drive account, you can find someone who allows you to borrow their machine to create a macOS account. You can then log in to that account, link your iCloud account, and see total and manage iCloud Drive storage directly.
By default, this temporary macOS account will try to download a lot of material that is linked to your iCloud account. Make sure in the iCloud preferences panel (Mojave and earlier) or the iCloud section of the Apple ID preference panel (Catalina) that you uncheck everything except iCloud Drive in the list of services to be synchronized. Then click Options and check the Optimize Mac Storage box. This will minimize every download, while still allowing you to calculate the size of nested folders and delete files and folders.