People have been aware that lies can be typed for as long as we've had typing, but it still works. The fact that it still works a lot of the time hasn't ended the world. People are more aware that they can't trust a photo, yet people still fall for edited photos, and the world still turns. I don't think deep fakes are any different. Videos were not very trust worthy before deep fakes. Special effects have been a thing for many many decades. The world is still learning exactly how untrustworthy video is and there will always be people who fall for tricks and manipulations, but eventually the majority will adjust and society won't crumble.

We'll put our trust in what we see with our own eyes and in people and organizations who have proven themselves to be trustworthy. We'll worry about how real something is in proportion to what it would mean to us if it were real. When it really matters we'll trust experts to authenticate a photo or video as legitimate just like we do currently. If the world becomes less dependent on information presented in formats that can we know can be convincingly manipulated we'll all be better off. History tells us technology like this in the hands of the public won't cause people to abandon faith in everything and anything they see, or destroy civilization. We all just get a little more savvy, more industries will take advantage of the cool tech, lots of people will have fun and games with it, not much really changes for most people.