It doesn't take a lot to damage a non stick surface. Absolute commitment to never using metal utensils is necessary. I've never been able to muster that level of commitment.

Seems to start out by using a fork to prod or move something, keeping away from the surface. Then there is that accidental contact that didn't seem to do any harm. Next thing I know food sticks and I've been stirring with whatever is to hand.

The thing about most plastic utensils is that they can't be left to sit in the pan while the food cooks.