Photoshop and similar applications did allow misinformation to be made. But not even 0.01% as much as AI-powered deepfakes as we see today. Photoshop took time, skill and had limitations. The worst someone could really do before was photoshop your head onto the body of someone else.
Now videos that look 100% real can be generated at lightning speed with no effort. Think of a celebrity, or a politician. Half a decade ago if you saw a photo of them you could be pretty certain it actually was them. Now you can’t. Half a decade if you heard an audio clip of a particular person confessing to something you could be almost certain it was them. Now you can’t. Videos and audio used to be pretty reliable before. Now they’re useless. AI deepfakes makes misinformation 1000X worse then Photoshop ever did.
It's sensible to think that it is possibly one of the reasons of the Great Filter.