Sidenote, you may expect we would call the breath the subject of meditation rather than the object. The reason for this distinction is that you are the observer of this object, making you the subject of conscious experience. This may help you understand strange terms like the subject-object gap and non-dual awareness when you come across them.
Sidenote: this is where self-dissolution and non-dual awareness come into the picture. When you glimpse being aware of the entirety of conscious experience... There's no room left for "the ego" in that moment.