As a non-native english speaker, I would say that even if the human has used an LLM to polish his writing, you are still interacting with a human. I use LLMs to polish my words (not the ones here on HN, but the words on my blog), and i have to iterate a lot until it writes the message (or tone) that I really want to convey.

But yeah, a blog post is not a short message. This one here is a short message and I didn't use any LLM. But I can guess that people that are not so fluent in english as myself may need it..