I think this is bigger than just swapping out actors for algorithms. It requires an entirely different kind of creative ecosystem. While traditional actors rely on makeup artists, costume designers, and directors, AI actors demand skilled professionals to bring lifelike appearance to AI models and to train them in movements, expressions, speech, and even to adopt a personality. In addition, they need legal teams to navigate rights, usage, and even content to avoid lawsuits.
There will be loss of work in some acting professions, but other jobs are now created behind the scenes that never existed before. It seems every aspect of life continues to evolve, and when it does, things get shaken up. Talkies replaced silent films, technicolor replaced black and white, etc.... I remember when digital music began to replace analogue, and VCR's gave way to DVD's, and cassette tapes surrendered to CD's, and streaming is now replacing a lot of cable.
Now that AI is taking the stage, the industry and content will have to adapt. Perhaps actors and actresses will become coaches for the AI models, IDK. However, I do think something will be lost along the way. It always is. Even with silent films, or Film Noir, there was something about them that set them apart and made them special.
I think actors and actresses draw on a lifetime of experience that can encompass a wide range of emotion. Even if AI actors can seem lifelike, I'm not convinced that some of the humanity that is etched in the souls that have had their reign in films won't be lost in transition. It may be simply irreplaceable. Actors are more than just images on a screen. They are real people shaped by life, loves, tragedies, fears, hopes, etc...., and when they bring all that to the screen, you can relate if you've ever lived life.
IMO, AI has some big shoes to fill.