Welcome to the forum!
You can turn off the donation messages on the main Settings screen.
This is because of how Duplicati’s backup engine works. It breaks up all your files into chunks and packages them into volumes (dblocks). No chunk is ever uploaded more than once, giving you efficient deduplication and versioning. (You can read more here.) When you want to restore something, use the web UI and Duplicati will download what it needs – don’t worry about working with the back end files directly, let Duplicati do that for you.
CloudBerry doesn’t do deduplication across files like Duplicati. With CloudBerry you do see files and folders on the back end that mimic your local disk, but the negative is that you end up with a LOT of files: if you are backing up X files and keep Y versions, you end up with X*Y files on the back end.
Are you looking for a backup product that keeps files in native format on the back end?
Absolutely… someone made a nice writeup here.