On your last point, it's because that's how physicists describe the nature of matter. Most of us think of it differently for everyday purposes.

On your first point, physicists spend a lot of time speculating on how to interpret the experimental findings of quantum physics. The fact that there are various interpretations suggests that what they are talking about is not observable. You can say, if you wish, that this is not physics. It is nevertheless physicists who are doing the talking.