Durability is used here as a blanket term, as if the word doesn't span a range of possible issues. Saying that the 17 Pro is more durable because the glass takes longer to break is in fact superficial, because it ignores different people's use cases. Personally, I've been using iPhones since the 3G and I've never had any phone bend, no cracked glass, just the usual scratches and possibly minor dents, depending on the model. So I would be more concerned for those than the glass breaking. It means nothing to me that the 17 Pro needs more drops for the glass to crack if it will be scratched and scuffed and dented more easily, because for me that is durability that I care about. I'm not taking the phone to a construction site or a war zone, something breaking my phone in half is not a concern, but having dented edges because of softer aluminum is very much a concern as I don't want to see that on such an expensive device.