I have been thinking over this comment for a while now. I think yes, you are correct that thought is involved in writing but I don't think it is possible to claim "all writing is thinking when done by a human". Like what type of thinking are you claiming here?

Because one can copy a text and write it down and that involves thinking in the sense that anything we do involves thinking fundamentally. But that thinking is different from thinking logically about a concept and writing it down which I think is where you are getting at.

The definition of writing and thinking is too broad in that sentence even though it does apply in several obvious cateogires within that at different levels.

And also "writing helps us think about the world" is too broad again. Why? Why does me writing "apt apt apt apt apt apt apt" help me think about the world? I just wrote it because i felt like writing it. Why wouldn't you consider that writing?