While iPhone itself is pretty secure as a device phone (and Apple makes sure to remind you about that in each ad, public speaking, attacks on competitors, etc), as an ecosystem it's not secure. And it's like that on purpose - there's no good and easy option to backup your phone other than iCloud.
You have to be a tech person to know how to keep an iPhone secure. Average Joe buys iPhone and pays for iCloud. They Apple first $1k to get (on top of other things) a secure device, and then they Apple monthly fee to give Apple all their data and make insecure. Pretty genius business strategy.