Most of the time the LLM version isn’t the one there. It’s “It’s not only XXXX, it’s YYYY.”

Also I noticed I almost wrote exactly the same pattern as the one OP pointed out.

To showcase it, I prompted chatgpt to write me a few paragraphs on the importance of radio astronomy.

I already thought it somehow stopped doing that, but then, in the conclusion, it wrote:

In short, radio astronomy doesn’t just fill in the gaps of our cosmic knowledge—it opens entirely new windows into the universe.

Which follows the same pattern.