And it's a tradeoff. I found out the hard way that newer Pixels have incredibly soft screens to avoid cracks and shattering. Unfortunately, they're so soft that a fingernail (a 2.5 on the Mohs scale) will leave huge gouges quickly. Fortunately, there's third-party covers that use an adhesive that fills in the scratches well.
Think about it; you couldn't put a fingernail scratch into a cheap soda glass beer bottle. Why would Google make a phone with glass that could be scratched by a nail, let alone easily? Does that even exist? Perhaps there is some coating on the glass you didn't remove and that's what you're scratching?
I'm sorry if you don't believe it, but it really happens. The "coating" would have to be pretty thick, this gouge was something you could easily feel with your fingertip. I was very careful to not let my keys or anything else get near it, and the gouge (which was essentially the only scratch on the otherwise flawless screen) was exactly where my thumb hits the screen.
My Pixel 4a, meanwhile, was in my pocket all the time and never got a scratch.
