Youe mistake is assuming execs care about "better". In a capitalistic Industry like Hollywood, better doesn't mean better quality, it means better profits regardless of quality.
If corporations could put out an AI show that is absolute drivel, but saved them enough money to where it maximizes a profit, they would. No question. So for writers, it isn't about the gap in writing quality. Its about the fact that you have to pay a human to written for you and you dont have to pay a machine to.
If thats the case, I dont think the average media watcher cares.
The biggest best selling movies are superheros, animated films, and various Lord of the Rings style epic adventure movies. And Avatar.
None of these have great writing. In fact, most have awful writing. Or the most predictable plot ever. Same goes for tv shows. Even a movie I liked Top Gun Maverick didn't have epic scripts. People seem to care more about CGI, well known actors, big battle scenes and cut and paste animated movie plots (good guy beats the evil warlord and there might be a price/princess part to it). Media is entertainment. They want fun. Professional top end writing does not equate to fun for a lot of people.
It's like what do people want? McDonalds, 5 guys, or a pub burger? The best one is probably the pub burger, but some people prefer Big Macs.
The movies that seem t have the best scripts, critics choice, and awards are movies that seem to make hardly any money. So it shows the average consumer would rather watch Captain America tagteamed with Tranformers battle against Magneto and Cobra.