Thought about this from seeing this Deepfake of the Queen dancing. For all the scaremongering, deepfakes haven’t been properly used.
We haven’t seen any deepnudes released of politicians, that one AOC thing a while back aside. We haven’t seen any deepfakes of Trump calling for a race war. We haven’t seen deepfakes of Bill Gates confessing to infecting everyone with 5G, or Biden confessing to being a corporate stooge.
What gives?
A buncha reasons I think, though I reckon we might start to see more and more of it in the years to come. Firstly, you don't need to. Look at how many people believe the most obviously manufactured bullshit about anything you care to name. The kind of people who would believe Bill Gates is putting microchips in Covid vaccines don't need a deepfaked video to 'prove' it.
Secondly I don't think we'll ever really see it used in the way you describe, e.g. putting one person on the spot. Those sort of attacks are always hinged on making someone prove a negative. 'No I never said that and here's a buncha computer scientists we asked to test the footage and it's fake' is too easy an answer. Sure I can see something like that crop up on some boomer facebook group but the people who'd believe it wouldn't need the video to convince them.
Deep fakes might some day form part of a much larger propoganda effort, I dunno maybe if the tech had been around in the early 00's then a deepfake 'smuggled footage' of Iraqi scientists making sarin or something might have formed a very small part of a bigger push.