https://it.slashdot.org/comments.pl?sid=17013741&cid=60424113
Much more detail at the link.
The fatal flaw that makes iCloud nearly useless as a backup solution is that it does not keep prior backups. As soon as you make a new backup, your old one is gone. And your phone is backing itself up to iCloud daily, in a manner that is outside the user's control. What this means is that as soon as something goes wrong, you have to IMMEDIATELY stop everything you're doing and wipe your device and restore the whole device from the last backup, or your data is GONE.
Much more detail at the link.