I published a magazine for ten years, and this was by far the hardest editing challenge we had; our authors were from all over the world, and some of them had to be pretty heavily edited because English was very much not their first language. Thankfully, we had really good editors who did a fantastic job of it… nothing would have killed us faster than a heavy-handed attempt at “normalizing” the content to a house style.
That said, context is also important. The vast majority of content of social media is of both low quality and marginal importance; style and character are important to make an impact, and AI is clearly not going to improve either.
On the other hand, functional communication, when the goal of the content is to simply pass information across and style is not as important, can, in my opinion, benefit from an AI polish, because so many people struggle with writing clearly. In those cases, I'd rather read slop I can understand than original content that is hard to parse, much like I'd rather read naïve code that you can easily follow than cleverly optimized code that is incomprehensible.
I take a different stance on your final point. I think people should absolutely not use AI tools for functional communication as a crutch because they struggle with writing clearly.
They need to learn to write clearly. I believe there's a direct connection between clear thought and clear words.