But if you also have a ton of photos and videos in your camera roll and want to preserve those, a local iTunes backup is the only way to do that without paying

But if you also have a ton of photos and videos in your camera roll and want to preserve those, a local iTunes backup is the only way to do that without paying for extra iCloud storage. Some people are also reluctant to store backups in the cloud in general for valid security concerns. WiFi iTunes backup has never worked properly for me even on 802.11ac, timing out and failing to complete more often than it works.