It's called the human condition, m8.
She is everything you said, and yet, Shirogane is what she wants, and for all of her planning, and keikakus, and assets available to facilitate her will, it is all counting for shit when it comes to getting the guy she wants.
Part of the charm of the series is that these kids believe that one is always going to be the subordinate, and the reality is that any successful relationship always has the controller and the controllee, the giver and the taker. The thing is though that it is always changing. Life happens to both people, and sometimes one person is knocked on their ass, and the other has to pick them up. Other times it is the other that gets knocked on their ass, and the first needs to be the one that picks them up. I am skeptical it will happen this way, but at some point, if Shinomya and Shirogane are meant to be together, at one point or another she will need to shed her privilege and everything you clearly don't like about her, and allow herself to be exposed and vulnerable to Shirogane, as he will also need to do to her, because if neither is willing to do that, it was only ever infatuation and nothing sincere. With that said, until the sweetness of two people, regardless of their station in life, caring about one another, but being unwilling to admit it is ruined by a creative choice I disagree with, I still think the situation is cute and funny and worth enjoying.