I specifically mentioned mounting (https://rclone.org/commands/rclone_mount/ which may use some additional storage space depending on the caching configuration) whereas you seem to be talking about mirroring the data in the cloud and on other devices.
From what I understand it's their friendly interface that differentiates them from RClone mount. I've only read their documentation but otherwise I can't see any benefit and only the risk of getting involved with a less tested tool.
Yup, it's also very useful for doing stuff like checking archive integrity after upload (got bitten by it once when uploading some archives via FTP) and syncing with cloud - I've had a dedicated client remove files from my PC instead of the cloud after desync, rclone makes it easy to check what will be done and works with pretty much every service available.