You outlined exactly why I still need a case. Ironically, I didn't feel I needed one prior to the 7 when I had a 5s. The rounded edge design of the 7 made it harder to hold securely (for me at least) so I got a case simply to make it less slippery. It may have also been due to the phones being larger. I was happy when the 12 returned to the flat edges but it still felt too slippery in my hands, even the mini. So I found a super slim case just for gripping it better. The screen is just fine, but I have noticed plenty of scratches on the frame.