It doesn’t share the wireframe of your face. It shares a generic face wireframe morphed to fit on your face. This wireframe lacks details that could be used to

It doesn’t share the wireframe of your face. It shares a generic face wireframe morphed to fit on your face. This wireframe lacks details that could be used to identify you in a way FaceID does. This is not worse than letting the developers access front facing camera to take a picture of your face.