Have had the ultra since launch and started getting scratches very quickly. Have owned 3 previous samsung flagships and not had any problems. The problem has only continued to get worse and I'm at the point now where I notice it every time I use the phone. I saw this post about how it's could be a thin screen protector that some had installed from factory. That would make sense except that I've looked under a literal microscope and can't see any screen protector or at least the edge of it and the post otherwise provides no instructions for how to remove it. My father and I received ours at the same time and he hasn't had any scratches (and he's much rougher with his phone) so I'm inclined to believe it is just a thin protector but I'm at a loss for what to do about it.
I went from a pixel 4a as a mechanic to the 21 ultra as a driver and my now dirt, oil, and solvent free hands still have somehow accumulated infinitely more micro scratches in a couple months than the 4a ever had for it's entire life.
The only way to really prevent the scratches is to get a tempered glass screen protector, which will ALSO render the awful in screen thumb print sensor