A scratch or a stone chip means material has been removed. Small scratches might be buffed, but filling is better. When I was a kid I would go to the druggist and buy some cerium oxide and buff the windshield scratches out by hand. It took lots of rubbing.
The thing to remember with a windshield is not to get near it with any tools. The least bump can cause a crack
Have you checked with your car insurance? It’s not at all uncommon to be able to replace even the most slightly damaged windshield at little or no out-of-pocket cost.
Some states, such as the one I live in (SC) have laws requiring insurance companies to pay 100% for windshield damage, including replacement. Some people take advantage of it, getting a new windshield when their old one has gotten scratched through the years.