Completely new formula glass on iPhone 11 and 12 Series phones. The 12 is slightly harder to scratch than the 11, but both phones are easier to scratch due to the new Corning glass used on all the high end phones these days from Apple, Samsung, Google, etc., which is harder to shatter, but a bit easier to scratch. It's not possible to make glass harder to break and harder to scratch at the same time.
I've only owned one iPhone which I didn't put a screen protector on. My iPhone 6 was naked for one year. Big mistake. At the end of one year, it was all scratched up and I vowed that no phone I ever bought new would even be turned on without a screen protector.
Get one either from Amazon or have one installed at your Apple Store to avoid getting any new scratches. And the screen protector will undoubtedly hide the ones you've gotten already.