Yes -- give it a try. My iPhone 7 Plus was nearly out of storage space, and also rather sluggish. Much of the storage space was being consumed by internal Apple

Yes -- give it a try. My iPhone 7 Plus was nearly out of storage space, and also rather sluggish. Much of the storage space was being consumed by internal Apple files according to usage details within the Settings app. After doing a full backup using iTunes, then resetting the phone to factory conditions, and finally restoring the iTunes backup -- my storage space returned to normal, and the speed increased dramatically. I suspect that over time, internal files accumulate (e.g. log files & upgrade restoration points), and this accumulated cruft gradually consumes space & degrades performance.