Phones could allow much higher security if they supported 2 factor authentication. This could be face/fingerprint along with a typed or swiped password. This seems like a simple solution that leverages software that is already implemented. Just make it an added option in addition to the existing ones.
Now that I think about it, there is a problem: fingerprint & face ID are not 100% correct all the time, so they’d rather have false negatives than false positives, i.e. they’d rather deny access to someone who is authorized, rather than grant access to someone who is not. This is normally not a problem, cause if for whatever reason the biometric method doesn’t work (e.g. wet fingers, wearing gloves, wearing full face mask, etc) then you always have the PIN/passphrase … but with your 2FA idea this wouldn’t work anymore.