Doing exactly this, replacing stunt doubles, is what I wrote and acquired a global patent back in '08. I tried to create a personalized advertising agency: put people into the advertisements themselves, driving the new car, wearing the new fashions, taking the luxury vacation. Problem was, I started my effort in '04, had a working pipeline by '08 - but none believed it was possible. Even when I'd demonstrate right in front of them, investors thought it was a trick. I eventually went bankrupt and quit. Today, we have deepfakes, where we could have had personalized adverting a decade ago.

That is neat and all but do we want that?

For the fashion industry, it becomes a fantasy visualization platform - see yourself in all manners of clothing, hair and makeup.

And replace the low paid actor's face with a high paid actor's face...

Savings! You also can produce movies then in low-payment countries.

This has been routine in films since at least Jurassic Park (1993).