Physically, it's impossible to scratch the screen with coins. Something else is causing the scratches.
Quartz sand usually does it where I live.
Time for my annual rant lol -
I can not stand youtube videos claiming to be tests when they're just demonstrations. They're just exercises in ego and click bait.
And a slap in the face to actual test engineers.
Glass is glass.
When someone releases a full table showing which materials scratched it and under what pressure that will be meaningful.
When someone releases a full table of low and high acceleration impact pressures with respect to multiple axes of application that will be meaningful.
Number of phones and youtubes for them released annually since the advent of wunder glass claiming no scratches or breaks - every one of them.
Number of phone forums here with owners as mad as wet hornets because the wunder glass on their new phone scratched or broke when youtube videos "proved" that was impossible - every one of them.
Number of forums where mod staff have to extinguish wunder glass flame wars (while in turn getting flamed privately for being on the company's side and part of the Great Conspiracy) - every one of them.
It's glass.
No adult needs to be told what their personal relationship and luck with glass is.
If you think you don't need a screen protector or case without the influence of the internet, chances are really, really high that you don't.
If you think that you do need a screen protector or a case from your experience or intuition, chances are really, really high that you do.
If you think that someone having an issue that you don't needs to be flamed, remember to tell them what the only correct dog to own is so you can see how silly your participation in a flame war is. (It can't be raining where you are, you idiot, it's sunny here! That's the essence of all flame wars.)
I think that it's great that they're improving the materials, I really do.
But the rest is simple. In my opinion.