Degenerate.

12 Mini here, 14 months in use (bought refurbished). Had to change my screen protector 5 months ago because I did a terrible job glueing the first one.

Had a protector on my huawei before, same protector for three years straight, none to mild scratches only.

Just invest the 15$ for a quite good one (most come in a pack of two). You won’t regret it, but please don’t put your keys in the same pocket as your phone. The camera is not protected whatsoever.