[quietbritishjim]

> Just informing them of that possibility will render such evidence basically useless.

Is a verbal statement from an impartial witness useless? What if they say recognise the defendant as the criminal they witnessed? Obviously it's not as ideal as unfakable video evidence, but it is useful and has been the basis of legal systems for the millennia before computers and photography arrived.

Fakable video evidence is somewhere between these: you still have to account for the possibility that the person isn't honest, but don't have to worry about the fallibility of human memory.