So, my caseless iPhone 12 mini has taken two falls to concrete this summer. One was on my back patio onto exposed aggregate concrete (the rough, stone-faced kind). It left one little mark on the aluminum frame on the back. I did have to lightly file it down as it had a sharp point on it (which I think was actually caused by the edge of the table it slid off of). The second was this last week. Face down from about 4 feet up onto smooth concrete that was somewhat dirty. Of course, it spins and slides, and left a nice circular scratch from the earpiece speaker down to the middle right edge.
I must say, these new iPhones are way tougher than the 6/6s/7, but nowhere near my old Motorola flip. I dropped that thing in the driveway one day from ear level and it didn't leave a mark. Of course, the battery was launched 10 feet across the driveway, which I had to find and put back into the phone.