Star Wars certainly didn't use deepfakes because they though it was cheaper or easier.
Star Wars certainly didn't use deepfakes because they though it was cheaper or easier.
You can look at voice acting as an example. Before Robin Williams' performance in Aladdin started the trend of recognizable celebrities as voice actors, there was a thriving community of voice-only actors in big-budget movies, hired for their craft instead of their brand. And yet, you probably can't name a single one, despite being able to name plenty of actors from non-animated films of the era. They were also inherently replaceable, as memorably parodied by the simpsons: https://youtu.be/g5ffaTv4ajg
It's notable that the studios switched to celebrity actors precisely for the brand that they brought from their non-voice roles.
Deepfakes are pretty much identical to this animated case, allowing it to be extended to physical movies. The recognizable portion of a performance becomes a few model files instead of an actor's face, and the job of a (replaceable) human actor is to play the role of the performer, not just the character.
Saying deepfakes makes actors superfluous is like saying synthesizers makes musicians superfluous.
I guess such an AI would also be able to write and direct the movie.
But yes, everything you mention up to and including writing and directing can and will be automated to the fullest degree possible in time.