As someone who works in content marketing, this is already untrue at the current quality of LLMs. It still requires a LOT of human oversight, which obviously it was not given in this example, but a good writer paired with knowledgeable use of LLMs is already significantly better than a good content writer alone.
Some examples are writing outside of a person's subject expertise at a relatively basic level. This used to take hours or days of entirely self-directed research on a given topic, even if the ultimate article was going to be written for beginners and therefore in broad strokes. With diligent fact-checking and ChatGPT alone, the whole process, including final copy, takes maybe 4 hours.
It's also an enormously useful research tool. Rather than poring over research journals, you can ask LLMs with academic plug-ins to give a list of studies that fit very specific criteria and link to full texts. Sometimes it misfires, of course, hence the need for a good writer still, but on average this can cut hours from journalistic and review pieces without harming (often improving) quality.
All the time writers save by having AI do legwork is then time they can instead spend improving the actual prose and content of an article, post, whatever it is. The folks I know who were hired as writers because they love writing and have incredible commitment to quality are actually happier now using AI and being more "productive" because it deals mostly with the shittiest parts of writing to a deadline and leaves the rest to the human.