The left most one is unused. The remaining 3 are each have a few thousand rounds (less than 10,000 each).
Although the wear on the 3 may not look like much via the pictures, seeing them in person seems a bit excessive esspecially only after a few thousand rounds. Maybe after 20K rounds or so, it would look normal, but not after just a few thousand rounds.
I have run my fingers along the rails in the upper and they are smooth.
Is this what your blish lock looks like after a few thousand rounds?
