Apple issues Mac 'Device Support Update' for restoring iOS, iPadOS devices
A new Device Support Update is available for Mac via Software Update, and Apple says it addresses restoring and updating the iPhone and iPad.

System Update
Apple's Software Update, in the Mac's System Preferences, is now showing a new option alongside the familiar macOS Big Sur updates. Called "Device Support Update," it appears to be an additional fix for problems with devices being updated via Macs.
"This update ensures proper updating and restoring for iOS and iPadOS devices with a Mac," says Software Update.
Typically these features are part of a regular software update, rather than being released separately. Apple notes that the update requires 195.7 MB disk space.

Software Update contains a new option
While the overall description of the additions is clear, at present, there is no specific detail of what problems are fixed, or if this is a specific fix for new devices like the iPhone 13 and iPad mini given that macOS Monterey has yet to debut. AppleInsider has reached out to Apple for more details.
Read on AppleInsider

System Update
Apple's Software Update, in the Mac's System Preferences, is now showing a new option alongside the familiar macOS Big Sur updates. Called "Device Support Update," it appears to be an additional fix for problems with devices being updated via Macs.
"This update ensures proper updating and restoring for iOS and iPadOS devices with a Mac," says Software Update.
Typically these features are part of a regular software update, rather than being released separately. Apple notes that the update requires 195.7 MB disk space.

Software Update contains a new option
While the overall description of the additions is clear, at present, there is no specific detail of what problems are fixed, or if this is a specific fix for new devices like the iPhone 13 and iPad mini given that macOS Monterey has yet to debut. AppleInsider has reached out to Apple for more details.
Read on AppleInsider
Comments
The iOS 15 upgrade form my iPhone took forever using iTunes.
I got error messages saying I needed to Restore it to factory settings.
Kept tryin, 3 times, until finally it ran the upgrade.
Maybe this fixes the problem?
Haven't had problems with any of my iPhones backing up locally, just my iPad.