> all video and image testimony becoming unreliable

This is a "seismic shift" in the sense of the Big One hitting California. The knock on effects of trust erosion caused by AI are going to huge and potentially unrecoverable.

I mean, you just outlined why it won't be a seismic shift: the only way the videos reliably stay on-model is if that model violates someone's copyright. And then when the movie is made the output itself isn't copyrightable (the ultimate arrangement may be but no individual frame is).