Apple Watch Series 3 38mm Stainless

I see what you mean. I can only imagine that damage by something like scraping on a wall, and it would be difficult to do that without also losing skin from the hand.

I think you have to live with the damage unless it is actually blocking use of the device.

The screen is sapphire but it also has an oleophobic coating to reduce fingerprints and smearing. The coating is much softer and is designed to wear away slowly over the life of the watch, so it will show minor scratches but this doesn’t prevent it working.