Optimizing iCloud Drive Storage: A Comprehensive Guide to Managing Synced Data on Your iPhone

Please refer to the two sets of pics one below the other.

1. The first set of pics on top Pic 1 Green (iPhone Storage): When you open iPhone Storage and tap on iCloud Drive you will see a message that reads "Your most recently accessed files are downloaded to this device for quick access. The original files remain safely stored in iCloud." The pic shows 7.22 GB of iCloud Drive data. This figure remained the same even after turning off iCloud Drive Sync.
2. The second set of Pics at the bottom Pic 2 Blue (iCloud Storage): When you access iCloud Storage on your iPhone with iCloud Drive Sync enabled, you'll notice a comprehensive list of apps currently undergoing synchronization with iCloud Drive. This synchronization is contingent upon your data interaction within these apps. Should you decide to disable sync for any particular app, the syncing process halts instantly. Nevertheless, the residual data generated by these apps before disabling sync persists on your iPhone for a brief period, extending until you cease further interaction with these files. This transitional period serves as a temporary phase during which the residual data gradually diminishes, ultimately aligning with the disengagement of iCloud Drive sync for the selected applications.

You may try experimenting with this as follows:

1. Settings > [Apple ID] > iCloud > iCloud Drive > Sync This iPhone [Enable]
2. Wait for "Apps Syncing to iCloud Drive " to populate.
3. Tap on it. Note all the Apps that sync to iCloud Drive.
4. Settings > General > iPhone Storage > iCloud Drive [Storage Size: Note it down]
5. Settings > [Apple ID] > iCloud > iCloud Drive > Sync This iPhone [Disable]
6. Settings > General > iPhone Storage > iCloud Drive [Check and compare the Storage]

The disparity in iCloud Drive storage utilization on your device remains minimal whether iCloud Drive is enabled or disabled. In practical terms, the impact on your local storage experience is negligible before and after toggling the iCloud Drive sync functionality.

Do the following only after taking a current backup of your device either on iCloud or iTunes.

By removing the applications (from this example: Books, iMovie, Numbers, and WhatsApp) that were previously synchronized with iCloud from your iPhone, you effectively eliminate the associated data stored in iCloud Drive with your iPhone. Consequently, the storage usage indicator on your iPhone, about iCloud Drive, will register a reduction to zero. This action optimizes your device's storage management, freeing up space and streamlining the synchronization between your iPhone and iCloud Drive. It's a practical approach to decluttering and ensuring that your iCloud storage is utilized efficiently.