This is honestly one of the very few use cases of cryptography signing a video or picture that I can see. But that would mean amateur journalists or the common person might be excluded from being a trusted source with video evidence.
All we are doing is trusting that the video images came from a given piece of hardware that we can trust belongs to me.
Whether I can be trusted is the same age old problem we have always had
But this simply makes it exponentially harder to fake or alter digitally any image (or at least look stupid when someone says "Citation Needed") - if you cannot produce the original raw footage questions will be asked why.
I can imagine this being something wanted on police bodycams quite soon