You won't know when we've crossed the precipice and it's no longer detectable. By now it should be clear that video/audio evidence without some other form of provenance is untrustworthy.
If I write here
"I love yellow snow" - Barack H. Obama
You don't look for signs of manipulation, you just wouldn't trust it at all without corroboration, I can type anything I like.
We use the opportunity to validate our biases and we become blind to evidence that would negate our strong feelings. It takes a conscious effort to evaluate and check the sources, once that visceral reaction occurs.
A relative hair-trigger on whatever emotions and preoccupations a person already has. These days, for the 99%, there's no lack of negative ones. But if you've ever been around a little girl who's just recently discovered a fictional world full of magical talking ponies and such...
The modern world's focus on no-risk, passive entertainment - at extreme scale. While our distant ancestors told stories around the campfire, and cheap novels & fiction magazines were pretty common over a century ago, the modern world's 24x7 feeds of TV, cable, streaming, social media, etc. is something else. And that content is for-sure not teaching self-awareness, nor self-control, nor prudence, nor skepticism, nor ...
But people still trust what they hear and see.
So audio and video clips get more trust than written words.
It takes a lot more time to get used to fake video and audio, especially in that mass and quality.
The same applies to quotes. You can trust, well, as much as you can trust Hacker News, that what I've written is what I've written. But you can't trust that what I've written is a true representation of a real event.
They are just marketing their products and services. They won't solve anything cause Media itself exists as Attention exploitation/manipulation service offered to the highest bidder.
Global Human Attention is a finite natural resource. Its needs to be treated the same way we treat water and uranium. Sooner or later we will get there.