In Google Drive web UI you can search "is:unorganized owner:me" that list all files owned by you with status orphaned (not belonged to any folder/not accessible)
You then can "Add to My Drive" to be able to access it or "Delete Permanently" which will free up your storage quota.
However above task doesn't always work in Google Drive Web UI because it is slow, it could result in "server error, please try later" which mean you can never see your orphaned files, or never able to free up your storage quota.
How can I do above operation within rclone?
At the very least I'd like to list all files I owned that is orphaned/not belong to any folder/not accessible so that I can permanently delete them.
Here is the typical example when orphan occurred:
User A create folder AA and share it with User B (read,write,view,dl permission).
User B create file B.TXT(read,write,view,dl permission) inside folder AA.
User A delete file B.TXT via Google Drive File Stream or Web UI.
File B.TXT became orphan, it still count towards User B storage quota and it is very difficult for User B to access it from Web UI. The file is impossible to list or access from User A perspective.
It seems that Google save all orphaned files as hidden files/folders in Root.