Yeah I think any additional security is good. At worst this could help in a lot of court cases. Someone presents photo evidence - it could be manipulated - it could be not. This happens already. Then someone produces an original higher quality version (like a raw photo - which I take even on my phone at all times now) and experts can verify that as the original.

And I agree on state actors. If a major one is invested in something like this they might have well compromised the signing project itself, the verification process, or even the court system or media. That seems like a rare and extremely high bar to guard against.