No, you're right. Writing is very expressive; you can certainly get that feeling from observing how different people write, and stylometry gives objective evidence of this. If you mostly let AI write for you, you get a very specific style of writing that clearly is something the reinforcement learning is optimizing for. It's not that language models are incapable of writing anything else, but they're just tuned for writing milquetoast, neutral text full of annoying hooks and clichés. For something like fixing grammar errors or improving writing I see no reason to not consider AI aside from whatever ethical concerns one has, but it still needs to feel like your own writing. IMO you don't even really need to have great English or ridiculous linguistic skills to write good blog posts, so it's a bit sad to see people leaning so hard on AI. Writing takes time, I understand; I mean, my blog hardly has anything on it, but... It's worth the damn time.

P.S.: I'm sure many people are falsely accused of using AI writing because they really do write similarly to AI, either coincidentally or not. While I'm sure it's incredibly disheartening, I think in case of writing it's not even necessarily about the use of AI. The style of writing just doesn't feel very tasteful, the fact that it might've been mostly spat out by a computer without disclosure is just the icing on the cake. I hate to be too brutal, but these observations are really not meant to be a personal attack. Sometimes you just gotta be brutally honest. (And I'm speaking rather generally, as I don't actually feel like this article is that bad, though I can't lie and say it doesn't feel like it has some of those clichés.)