The reality changes. Fast. You won't be able to trust photos, audio recordings, or videos. You will be able to trust digital signature. To have any opinion whether information about somebody else is real you will need a working web of trust. It's gonna be a great thing and I can't wait for it. It's going to change news, politics and in general the world we live in. It's going to be bigger than the Internet but way more polarizing and controversial. IMHO

One issue though, unless we hurry up and make this WoT decentralized and with open protocols, well, we will get it from FB and the likes.

Web of Trust and Reputation Networks.

To be perfectly honest, I've always personally been surprised at what business people are willing to transact over the low-bandwidth media of the telephone. I've heard plenty of stories of people pretending to be celebrities and getting away with stuff on the phone; I don't need a sophisticated computer to do that for me.

If a real problem of deep-fakes in phone conversations emerges, people will just raise the bar of authentication in phone communications. There's nothing magical about telephone that makes it exempt from the general need to protect against social engineering.