I'd argue that this type of AI frees up humans to be more creative. If a journalist doesn't have to spend time writing routine articles about baseball scores, they have more time to spend tracking down real stories. I posted elsewhere in these comments about my own AI-powered news system, and if I didn't have that my entire day would be taken up writing routine articles that are interesting to readers but have very little journalistic value. Instead I can turn on the machine and let it write this routine content while I go out and interview the city manager about the proposed development downtown or the upcoming tax increase.
If the routine and mindless tasks of humans are moved to automation, those humans are now free to actually create.
While I do agree with your argument to a point, it breaks down because the internet is a mountain of crap, and while attention is a limited resource, the crap is limitless.
You say you use AI to generate mundane articles. Well, your mundane AI article about baseball and 10,000 other AI generated articles are competing with quality content written by real people.
There are people who are passionate about baseball, who went went out to watch that baseball game and write about the passion behind every play and every ball. Possibly interviewing the crowd and the players.
Your AI is probably learning from those articles and getting better at faking that passion. So much so that in a few years maybe people won't be able to tell the difference.
In most cases, they are not competing, because the primary niche for NLG is to generate content that was never economical for a human to take the time to create -- minor leagues, fantasy football, etc.
If the routine and mindless tasks of humans are moved to automation, those humans are now free to actually create.