What damage? The grafts that are transected during the cut are not going to be implanted. And the damage is limited as it occurs on the edges of the strip. Once the strip is excised, the interior follicles can be dissected under a microscope, minimizing transection. On the other hand in FUE, each follicular unit is painstakingly removed piece by piece, and fatigue will have a role. If you minimize transection here, you end up with a larger punch, and if you use a smaller punch, then you risk damage to the follicle.
FUE has an important place in HT surgery, but it is not far superior.