Bottom line, there’s always a possibility a cloud/service provider could lose you data. That chance is (/should be) exponentially smaller on their environments however than the likelihood of your own local stores.

If you’re really serious about preserving your data, consider the 3-2-1 Backup Rule:

3 copies of your data 2 different types of media 1 copy stored off-site

Not who you’re replying to but yes, Synology will let you automate backups to a cloud/service (and you definitely should!)

Is that even possible?