You act like big budget action films are easy to churn out. They aren't. Transformers are fun movies to watch. There are plenty of action films that aren't worth a nickel. And hell, a franchise like Transformers isn't going to be sold to anyone just saying "we're going to let an AI write the script." It was given to Bay because they knew exactly what they were getting with him at the helm.
Yes. It would be awful. Why? We'll get to that in a second. As far as streamer - probably. Which would suck because they lap up anything Star Wars and it would show the mouse that oh all we need to do is slap SW on it and the dorks will buy it. But that doesn't make it good.
No AI can't make a show as good as CSI. And this is where I will pick up the SW argument too.
In the end it doesn't matter what you feed into it - all it can do is make near copies. "Give me a crime drama LIKE Breaking Bad", "Give me a period piece LIKE Mad Men", "Give me a procedural LIKE CSI", "Write a Star Wars sequel story". In the end it can only take what is there and at best churn out something that has the characters and has them do a lot of what you've seen. And it would likely be pretty hollow because you wouldn't see any sort of evolution of the characters from what they last were in the media.
What made Breaking Bad and Mad Men was their uniqueness and their characters. They evolved, changed and grew. The world changed around them and they changed to adapt. AI can't make any of that up. It would just regurgitate what we have seen ad nauseum. This would apply to Star Wars too. Take the entire SW catalog before 2022 and there is ZERO chance that an AI generated Andor would be anything but Andor flying around the galaxy with 17 Jedi pals. And it would be really dumb because everyone would be saying shit like "I am one with the force and the force is with me", "I've got a bad feeling about this", etc. I would probably rather watch fucking fan made films, which I detest.
Even trying to crank out a CSI clone - it would be like if CSI was written by the writers of The Princess Switch - let's just take every damn cliche of this genre and run with it.
In the end my main issue is the writing - that takes something that AI doesn't have and I think it will take sometime before it does. It might eventually, but until then that is something that needs to be left to a human. You want to take a script and run it through a film generator - you probably get something useable. But AIs writing scripts - that will likely be trash.