I also have an iPhone 13 Pro that was clamped to an aluminium holder like a vice WITHOUT a vibration damper (there was no rubber ring or anything like that anywhere). After approx. 1000 km, the new smartphone (image stabiliser) was then already ruined. I have a Honda CB650R, so it's a 4-cylinder with few vibrations, but they are very high frequency. Then I immediately changed to the Quadlock system with vibration dampers and the Pro Mount, which also uses a few rubber rings around the lender rod. After approx. 3000km I have not yet noticed any defect in the camera. So in principle it should at least be gentle, but whether it stays that way is another question.

I also think that it is very dependent on the motorbike (vibration strength and frequency) and the iPhone generation.
Because...

Previously, I had an iPhone XS with Apple Leather Case mounted on a KTM Duke 390 with a RAM mount that simply clamps the smartphone in place with silicone nubs.
There, too, I had no problems after more than 5,000 km. But I'm comparing apples and oranges here. The KTM is a 1-cylinder machine, and the iPhone XS certainly doesn't have such a powerful/susceptible image stabiliser.

My iPhone XS didn't survive without the shock absorber. I've had the 13 ProMax for a fortnight now, of course I only use it with shocks and have no problems at all. I ride a GS1200

So far, I have not had any damage to my iPhone7 despite the strong vibrating V2 motor. The part seems to be really useful.