Newly created accounts can't add comments, so I'm writing in the reply form. I ran into the same problem about 10 days ago. Just a regular Google account, not a workspace, was registered a long time ago, and an error about lack of space began to appear. After receiving additional information via Google Drive API, I saw that storageQuota.limit = 0, while there is disk space on drive.google.com

Part of the response: 'storageQuota': {'limit': '0', 'usage': '3040221', 'usageInDrive': '3040221', 'usageInDriveTrash': '0'}
Service Accounts do not have storage quota. Leverage shared drives.