It’s difficult to know whether people are putting their iPhones in cases because they want drop protection, or they want to keep it as scratch-free as possible, for as long as possible, or maybe to create some personalization, or some combination of reasons. I carry my 14PM both naked and in an Apple leather case (for the visual personalization) and would likely ditch using a case if they switched to titanium, just because I like how any smooth titanium object feels in my hand, plus I wouldn’t worry about it scratching as much.