Counterpoint: I think it can also useful to avoid LLM-isms because it's a quick test to check whether you're saying something derivative or actually saying something novel/interesting/significant. Which is to say, if someone could credibly accuse me of being an LLM, then that means my writing is no better (for whatever definition of "better" you want to use) than what happens when you melt down all of human language into a paste and then reconstitute it into featureless little cubes.
Obviously there are exceptions; you can use certain constructions in a way that's still unmistakably human, or use them within a larger context of unmistakably human writing. But in general it makes me think about Orwell's argument against cliches:
> A newly invented metaphor assists thought by evoking a visual image, while on the other hand a metaphor which is technically ‘dead’ (e. g. iron resolution) has in effect reverted to being an ordinary word and can generally be used without loss of vividness. But in between these two classes there is a huge dump of worn-out metaphors which have lost all evocative power and are merely used because they save people the trouble of inventing phrases for themselves.
If LLM-isms give readers the impression that I'm too lazy to phrase things in my own words, even if I did in fact phrase things in my own words, then I take that as a sign that I should pick better words!
Granted, I've had a strong desire to write as distinctly and un-cliche-ish-ly as possible since long before ChatGPT's public launch, so I might not be as grumbly as other commenters who feel like this would force them to change how they write.