If you're looking for a criticism, might I suggest, "won't somebody just print their photoshopped photo and then take a picture of that?". This criticism's semantic consistency would allow for such responses as "this could be remediated by signing additional data points such as time, gyroscope reading, and ...".

What I'm suggesting is about unfortunate centralization, the exact ideological antithesis of the technologies you are mock appreciating. I really wish I knew a better way. There's no distributed proof for truth.