Re: Wait Til Hollywood Gets Involved!
Whilst you are absolutely correct that great actors add more than just their image to the performance, that's still only an algorithm* away.
Alternatively you end up with 5 brilliant actors who do all the acting in every film and then the studio just maps the face and image onto them to get the final desired product.
We're already seeing de-aging used pretty successfully film and TV, it's not a huge step beyond that.
*perhaps quite a complicated one, but perhaps machine learning can be shown great films and great actors and adapt to understand what is needed to create that in a new film.