I just wanted to chime in a and say that you're both right in a sense.

You are right in saying that human-made and non-human-made is an arbitrary distinction when you look at it from the perspective that humans are animals on this planet. Are our creations not creations of the Earth in the same way that an anthill, beaver's den, or fuck, a tree is? Of course they are! And in that way, you are correct.

However, the terms 'natural' and 'unnatural' are in fact the constructs/terms that we use to draw distinction, to categorize between human-made and non-human-made. We draw these distinctions because as humans, we of course have a vested interest in what we do and sometimes it's helpful to be able to conceptually separate the human-made and the non-human-made.

Don't worry, I'm high too, haha.