I think the uncomfortable truth is that we're already there and it just doesn't matter because everything works on trust anyway. Sure, quality faked media has a ways to go before you're watching an Avengers quality deepfake porn but for groups that care to a professional degree (intelligence agencies, militaries, digital media companies, etc.) the quality is already good enough for intelligently planted media. The real limiter is access to trusted distribution channels for your faked media. A homunculi media consumer who gets their information from AP News/Reuters/Fox News/CNN/LA Times/New York Times/Verified Twitter Professionals/etc. is probably not at all in a position to judge the veracity of the material presented. If they were in a position to make such judgements they wouldn't need to care so much about whichprestigious media outlets they favor. But they do care, precisely because they know that they're gullible and so they want the media outlet that will give them the real truth (which usually means either the truth they like or the truth they don't like but from a brand that conforms to their ideals of what a news media brand should be). If CNN and Fox News both ran the same deepfaked video of Joe Biden shooting his veep with supplementary text stories and such then I wager a good portion of the American populace would believe it had happened and have serious conern.