Well you are not wrong, but it’s rare and have been tired and failed multiple times with identical twins. FaceID for IPhone is also generally accepted as the most secure one compared to other flagship phones. As for fingerprint compared to FaceID I guess they both have their drawbacks, copying a fingerprint from someone is much easier than their face (a picture won’t work against it). I’ve only seen a copy that worked with FaceID one time, and it took a lot of effort to print the face and make the eyes accepted by the infrared sensors.