Thanks to Apple's iCloud, keeping an always up-to-date backup of your iPhone or iPad on Apple's servers is nearly effortless. Ditto for restoring an iOS device from an iCloud backup. If you're a Mac ...
So I've always tried to follow the 3-2-1 rule for personal backups (3 copies of the data, 2 backups, 1 backup off-site). My NAS crashed a couple of years ago, right around the same time as a house ...