Because:
* Rclone offers client side encryption (with a good algorithm and from a good library). Cloud providers usually offer server side encryption, but don’t want to offer client side encryption.
* You can mount the remote. Files don’t have to exist on client’s side to occupy space. This tool mounts anything!
* You learn one tool and use it everywhere
* It’s is under user’s control. You run it with a schedule that you want. I don’t have to run a closed source app continuously scanning my computer
* Robust, feature full, open source (especially for verification of encryption), large community for getting help, and under heavy development Rclone combined with Restic is how I manage my data in the cloud.