- More secure (Face ID uses more data points)
- Less user-interaction to authenticate (though as you point out this is also a negative)
- Allows for other UX improvements, e.g., maintaining screen lighting while phone is being observed but not manipulated
- My speculation: capacity to add additional faces will be added with SW (or next HW) update
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I don't understand your point #3. How do you think someone would unlock your phone with Face ID?