I'm not saying we will specifically return to a system of only eye witness testimony. I'm saying that the age of self-authenticating evidence is over. Until recently, a video or audio recording was considered authentic on its own. It was an absolute source of truth, accepted prima facie.

This era is coming to an end. When we can generate any form of fake evidence, we will have to rely on reputation of humans. If you want to convict someone, a video will no longer be sufficient. You will need someone to testify that the video is authentic. And this testimony will be considered of the same class as a testimony from someone else claiming an alibi. Even with a video, that will only be counted as a single witness. If you have a personal recording that acquits you of the crime, it will be thrown out as evidence.