[jbay808]

I appreciate that humans are a part of nature. But "natural" and "unnatural" refer to valid, if nebulous, regions of concept-space that it is useful to have words for.

When your neighbour says she avoids putting chemicals in her food, do you cross your arms and say "even water is a chemical"? Or do you accept that her usage of the word points to a valid region in concept-space that isn't hard for you to understand, if you aren't hung op on dictionary definitions?

I wrote a cousin comment explaining why, despite the fact that humans are part of nature, there is a qualitative difference between human structures and beaver dams / coral reefs. It's not human bias, but human power and social structures that cause the difference. Or else, as I mentioned there, you're welcome to bring wire cutters with you on your hikes and treat fences the same way you treat other natural barriers.

This is also why, in a post apocalyptic movie, the decaying artifacts and skyscrapers of a lost society feel more like a natural landscape than artificial structures. It's because they lose the power structure that backs them.

Insisting on a useless definition of "natural" that encompasses literally every object in the universe just makes communication a chore.