Yes, glass can scratch, but the type used for the camera cover is more readily scratched than the surrounding Gorilla Glass, or other covers (glass or sapphire) on other phones.
No idea why LG went cheap with this important part because it's been driving us users nuts since the G2 days.
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I threw on a plastic screen protector cut to size and an ultra thin plastic phone cover on this week to provide protection and extra distance from tables while reducing the slipperiness. Hopefully, this will allow both the camera cover and glass back to remain in good condition until I upgrade.