It just depends on your abstraction you’re mentally using. If you think of a sliding moving visual window on a document, then you like the scroll bar mental model. If you think of moving the content itself, then you like the phone scroll model. I have no idea which one “natural” or “inverted” is and don’t really care what the default is.
For touchpads, give me the phone style scroll. For a mouse wheel, give me scroll bar scroll.
It does feel weird that middle click and then move the mouse (I think Firefox does that kind?) will move the view such that down motion movies content up. But instead click and drag (okukar browse function) upward motion moves content up. Again, just depends on your abstraction in that moment.