>they believed in photographic evidence in those eras because there was no convincing way to manipulate those on a large scale.

Again, are you trying to claim they believed in photographic evidence throughout all of human history.

>neither one will ever be believable again.

Not really. It just won't be believable from anonymous sources. When say, the NYT posts an article that Ukraine has blown up the Kerch bridge, it's much harder to just claim the photos are from some other incident then if some dude on reddit posts it. People already can claim anything they don't like is fake news, no matter the evidence behind it. Misinfo's strength is that most of info recieved in general from the same medium has to be credible and corroborated, or otherwise trustworthy. If nothing is trustworthy on the medium, the medium dies.

In non legal matters, people have always put more stock in individual trust and words rather than actual hard proof. Your own example on the election proved this where the people believing in the "hoax" idea lost dozens of court cases because they had no proof. They believe in it because someone they trust for whatever reason(despite him being a proven liar) said so.

Audio and video proof, which is rare anyways in most disputable cases , will become mostly contigent on the source. Like it mostly is today.