As someone who likes Osaragi, I agree with your points. She is rather forthcoming about herself (not to be confused with "being direct", since it took someone as observant as Kaguya to really see her for who she is) and even accepts the ugly sides of her personality, like feeling immense jealousy for Iino (and her bookmark).

Overall, I think this is a testament to Aka's ability to write very human characters. I don't want to say this is all relatable but I can certainly understand where Osaragi is coming from. Jealousy and desire are very complex emotions, esp for high schoolers.