Fingerprint is present in GrapheneOS. Face unlock and pattern unlock are left out because insecure. Patterns unlock is insecure in design. You start at a certain point and the next points you can go to are very limited (not the same point again and you have to be able to reach it). This makes it hard to make a strong lock. Face unlock is insecure because lack of proper hardware for it on the supported phones. Fingerprint is secure. Coercion can be worked around via 2FA feature (fingerprint + pass/PIN).