On my iPhone (iOS 14.1), in Settings > General > iPhone Storage, iCloud Drive is fifth in the list of storage space, at 1.84 GB. When I tap on it, it just tells me that "Documents & Data" are using 1.84 GB, with no further breakdown.
I'm a bit confused, as I hardly use iCloud Drive. When I look at the iCloud Drive folder on my Mac (macOS Catalina, 10.15.7), I've got 11 top-level folders; four are empty, and the biggest is listed as 8.7 MB. I've got one top-level file, a 1.4 MB PDF file.
Where is the 1.84 GB listed on iOS coming from?