-
rclone
"rsync for cloud storage" - Google Drive, S3, Dropbox, Backblaze B2, One Drive, Swift, Hubic, Wasabi, Google Cloud Storage, Azure Blob, Azure Files, Yandex Files
-
cyberduck
Cyberduck is a libre FTP, SFTP, WebDAV, Amazon S3, Backblaze B2, Microsoft Azure & OneDrive and OpenStack Swift file transfer client for Mac and Windows.
-
InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
Possibly the best way to do that is to use Air Live Drive (GUI) or Rclone (CMD line) to mount your Google account as a local hard drive. You can then research desktop folder comparison software that does what you need.
The only software that combines elements of both are Air Explorer and Cyberduck. Both will synchronize your computer with the same folder in your Google Drive and give you an overview of what files will change prior to starting the sync. But duplicates are only detected if they exist in the same folders. Dedicated folder comparison/duplication software is designed to look wider as it is comparing folders, not syncing them.