iPhone X has the speed of Face ID and Touch ID compared in a short animated image that tells us which of the two systems unlocks faster. As you can see in the video clip below, Touch ID makes unlocking faster than Face ID on the iPhone 8 Plus compared to the iPhone X.
iPhone X was presented by some reviewers as having Face ID as fast as Touch ID, but the reality is completely different. It is very easy to see that Face ID is slower than Touch ID for unlocking, especially since it requires swiping on the screen to unlock.
If Apple had thought of iPhone X with an automatic unlocking and display of the main application page when Face ID recognizes us, the situation would probably have been different. If things were like that, then the function that hid notifications for strangers would no longer be useful on the iPhone X.
Having said that, now you know what to expect regarding the iPhone X unlock time using Face ID.