because it's real!
Well because she reincarnated she knows details of the plot she wouldn’t have known otherwise. For example in the earlier chapters when the whole corruption arc started where her higher ups were trying to make her friend take the fall for everything they did she was only able to free her friend bc she knew how they had done things and even where to go to meet his majesty’s secret group. And because of all of that it piqued the interest of his majesty towards her
That plays a big part into the story, actually, since if she didn't know the story she wouldn't have been able to impress Kyle enough to have gotten recruited into the guild later on, and her prejudice against the emperor would've seemed unfounded and made her look merely prejudiced and shallow.
I really like the story but I think that the part that she reincarnated wasn't even necessary to the story man, why are they so obsessed with rencarnation