Backing up files and folders across multiple platforms is the best way to ensure nothing is lost.
Using just one backup method could result in instant data loss if there is a security breach or hard drive failure.
Relying on one backup method can be tempting as it is often the easier and more affordable option, however, if this method fails, it can result in huge amounts of time and money being wasted, as well as the possibility of losing old memories and photographs.
Using multiple backup methods helps to ensure that everything is backed up properly, that there is better security, less clutter, and that there is no over-reliance on the internet.
Cheap cloud storage is a preferable option to physical hard drives, as hard drives will eventually fail.
Having multiple backup methods also allows for working offline, meaning that an internet connection is not always relied upon.