If you call yourself a writer, having tell tale LLM signs is bad. But for people who's work doesn't involve having a personal voice in written language, it might help them getting them to express things in a better way than before.
Can we please stop propagating this accusation? Alright, sure, maybe LLMs overuse the em-dash, but it is a valid topographical mark which was in use way before LLMs and is even auto-inserted by default by popular software on popular operating systems—it is never sufficient on its own to identify LLM use (and yes, I just used it—multiple times—on purpose on 100% human-written text).
Sincerily,
Someone who enjoys and would like to be able to continue to use correct punctuation, but doesn’t judge those who don’t.
I feel the emdash is a tell because you have to go out of your way to use it on a computer keyboard. Something anyone other than the most dedicated punctuation geeks won't do for a random message on the internet.
Things are different for typeset books.