Once deepfakes become that widely feasible, people will post them on the internet for general amusement or other frivolous motivations all the time, and no one will take video at face value anymore.
It’s quite well done and I think it proves your point: general amusement, and now face value doesn’t work anymore.
You're assuming most people are rational, skeptical, and won't trust anything that doesn't have a valid chain of evidence or proof of validity behind it. That's incorrect - most people believe that about themselves, but still tend to take anything they're shown at face value if it aligns with their preconceptions and there is no emotional or social risk in doing so.
(Not safe for work. Not pornographic, just not appropriate for workplace.