The glue makes the device stiffer. If you want drop resistance you need rigidity or softness. A phone with glass won't be soft, so it has to be stiff. There ar

The glue makes the device stiffer. If you want drop resistance you need rigidity or softness. A phone with glass won't be soft, so it has to be stiff. There are ways to make a phone stiff, such as a rigid metal shell around the battery. Or glue.