That's tedious. Can't believe nobody mentioned Parachute Backup yet. It had a moment in the sun earlier this year or last year when it first started getting traction.

I have a Mac, so not just an iPhone, so I use Arq there, it materializes the iCloud stuff as necessary for backup. But if all you have is an iPhone or iPad along with an external disk, NAS or whatever, Parachute Backup will do backups to a variety of destinations.