The issue with AI is not that it will replace writers, it's that studios will create narratives with AI, then get writers to punch it up - and therefore pay the writers less. That's part of what this strike action is seeking to stop.
AI will never replace human writers, but it will impact on their ability to make money, by decreasing the amount of work. And poorly paid writers will not do a good job of improving AI generated story telling. If you support the idea of AI replacing any aspect of humans writing, then you're supporting the death of entertainment, and a guarantee that all you'll get from now on is MCU style, factory line bullshit.
And if the point of AI is simply to get the ball rolling and writers take over to do the meat and potatoes of it, that's tech. And thats life.
No different than any other job where a PC does a lot of the groundwork and a user swoops in, uses their brain and creates a final output.
As I said in my past example regarding finance, not only does every large company pay fees to use all the big wig programs that have been around for decades, but also pay money to small marketing and data companies to do the rest. This type of work is something more in tune to the past 10 years or so. You never had all these companies offering these services 20 years ago. And surely not before I was working 30 years ago or more. The companies try to automate as much data as possible and offer canned templates (framework) so the user just has to churn out reports and analyze them. And if we want to do something more fancy with it, we use the data and do our own thing.
Not everything in the world has to be made from the ground up every time.
As for TV and movie plots, it's not like most of the content are pulitzer prize quality either. In fact, most content isn't even aimed at high brow consumers or experts in language and dialogue. If you want that, people should seek out obscure indie films or watch reruns of Masterpiece Theatre. It's often times generic plots, generic character names, and 99% of the time the good guy beats the villain to save New York City and one of the action scenes will have a helicopter shot down twirling to the ground doing 12 revolutions. Or it's the classic "man seeks revenge for killing wife or daughter" plot. Not exactly clever material.
If most Hollywood material has such common themes and plots, AI can churn out a bunch of stuff fast and everyone can see where it goes from there.
It's like AI art. How long does it take an artist to do a storyboard? I dont know. But not in 60 seconds. Maybe the game maker is looking for ideas and whats to use AI to shotgun 10 examples in 10 minutes. Pick one. And the team goes from there using that as a basis for art and characters. And if AI art is dogshit, then they'll go back to hiring artists to do it from scratch,
I'm not a artist, but if I was to make a game there's no way I'd draw shit by hand, nor hire someone to draw me some stuff when all I got is an idea in my head. I'd just use AI to give me some examples and I'd go from there adjusting it and pick one to use.