Earlier quoted context omitted.
Why bother? Actors cost money and scheduling is difficult. Do the whole thing in AI - the model will be trained on better actors than your indie cast, anyway.
It will be a loong time before AI can produce lead actors that are believable, act exactly the way you as a director want and tell the story you want to tell, so I think at least for now you'll still need the actors for the lead roles. But I can totally this being used for generating people/stuff in the background of certain shots in a low budget movie.
A "loong time" will be sooner that most of us think.
The way this is done currently is similar to motion capture except that the tools are gradually becoming democratized: A single actor can act all the roles you need (You could even act the scenes and roles yourself). That footage is then fed into a model that generates an actor with the appearance and voice that you desire.
As a random on the internet, my prediction is that within a year, you'll be able to produce lead actors that are believable using movie generation plus smartphone footage of yourself acting the scene.
Initially it will be expensive to make a feature length film. But from 2025 onward, the cost will come down as the tools improve. These will be a different type of movie for sure, but every advancement in film technology has always led to films that seem strange compared to what came before.