I got these screen protectors on amazon for $5 (back when I bought them) for a three pack and they've been great! The first one, the edges got chipped in a couple places when I dropped the phone on pavement, and eventually the whole protector cracked (still no damage to the actual screen underneath). And now I'm still on the second protector, which now has a couple minor scratches, but no chips or cracks. And I still have the third for when I need to replace it.

These cover the full screen of the XS (including the notch). And they come with a nifty little tool that helps align the protector when applying it to the phone.

Edit: The brand does exist outside of Amazon. Tethys. Although I think they sell their products entirely on Amazon.