Duplicati is not a file synchronization tool. It is a backup tool that utilizes deduplication in order to store many versions efficiently. Because of the deduplication, files are broken up into chunks for storage:
The encryption (which can be disabled) isn’t really the problem for you - it’s the deduplication. Deduplication cannot be turned off in Duplicati.
Sounds like what you are looking for is something to synchronize files in their native format. Which cloud back end are you using? We might be able to offer some alternate suggestions…
As @drwtsn32 explained, breaking files into chuncks of data is not the same as encryption. The files you see at the backend (*.dblock.zip) are unencrypted chunks of raw data that are used to rebuild the original files during a restore process. This approach enables deduplication and versioning of the backup data. If an additional extension .aes is added, the raw data is encrypted to protect the data against malicious persons.
If you want the source files to be copied straight to the remote location, Duplicati is not the tool that you want. You’ll need a synchronization program to do this, but probably you’ll loose the benefits of deduplication and versioning.