iPhone X and iPhone 8 pass the first comparison regarding impact resistance, both Apple phones being released this year, both with glass casing, after a very long time. Apple says that both the iPhone X and the iPhone 8 have the same type of glass, which should be very resistant, but there are some differences between them because the first one has a slightly darker gray than the first.
The iPhone X has a stainless steel structure that is more resistant to impact than the aluminum in the iPhone 8 case, so if you drop it sideways on a hard surface, it won't bend as easily. As for the case, it seems that the iPhone X is more resistant than the iPhone 8, the latter cracking from the first drop and leaving no pieces of the case on the second drop, something that should not happen normally.
iPhone X withstands well the first drop and resists the second drop without problems, being much more resistant than the iPhone 8, thanks to the stainless steel structure integrated by Apple. Dropping from a very high height does not seem to affect the iPhone 8 screen, although the case is completely destroyed, while the iPhone X proves to be equally resistant, the phone escaping without problems from every impact, even from head height.
The iPhone X does not crack, but the TrueDepth camera gave way after the impact of being dropped from the height of the head, so the device will have to be changed by the user anyway. Having said that, the iPhone X has a more durable structure than the iPhone 8, but in terms of internal components, the TrueDepth camera fails and requires the complete replacement of the Apple device.
