It’s one thing to make the device and hinge dust resistant, but that still won’t solve the issue of a folding mechanism being more prone to failure than a non-hinged device. And another issue with dust, sand, change, keys, etc. that may be in your pocket when you put a folding phone in your pocket, is the screen will also be subjected to these items and face both surface damage and fracture. Folding screen phones, including the iPhone, are not inevitable. We’re more likely going to see movement away from large screened devices with AR glasses coming into play.