Lots of folk (not solely non-technical) treat cloud sync as a backup - when often it’s not. Can’t comment on Fujitsi’s offering.

In any case it should only be one of the three copies of your data.

Anecdotally, photographers - especially professional ones , take backups quite seriously. I’ve often read good blogposts written by them on how to backup your images. And I believe the 3-2-1 rule originally came from a photographer Peter Krogh.