Are you serious? The screen still scratches very easy despite it being Gorilla Glass. Not from something like car keys, but from pieces of sand and dirt. My first (defective) phone, I decided to not use a screen protector and it gathered quite a few micro scratches in just a few days time. Along with the back glass.
I have my S6 Edge in a clear view cover case.
I had S1 for 2 years, S3 for 2 years and both of them have no scratches either.
I guess it depends on how you handle the phone. I keep only a phone in one pocket and no car keys or wallet or other stuff.