Been thinking about this more than I probably should, and what I find most frustrating about the writing of this arc, aside from Yamada not standing up for herself, is that ultimately the consequences of this whole thing are so skewed. This whole conflict is entirely of Kase's making, and she is the one with all the agency in resolving it. Yet it's Yamada that has the most to lose, and bears the burden if Kase were to fail, and that just feels awful.
If Kase loses and has to stay in the dorm, all she misses out on is not having Yamada to wake up next to every morning (a loss to be sure, but let's be real: it's pretty low stakes). Yamada on the other hand has been working extra shifts at her job for months to save up. She's been spending loads of time shopping for apartments, and running herself ragged in the process; all effort that would go to waste if Kase loses. She's the one who has been planning to move in for months, and has been actively working towards this goal while Kase does nothing. And let's not forget that she ran a real risk of being homeless if she hadn't been able find another apartment after losing the first one, or if Kase wasn't going to be around to split the rent.
And this is just made worse by the fact that it's Yamada who we constantly see struggling. We see barely any of Kase's training, and she always seems to be not serious the few times we do. This arc would have felt a whole lot better if instead of constantly having to see Yamada be the victim of Kase's stupidity, we had instead seen more of Kase struggling and having to overcome adversity. As it is now, it feels like we're supposed to swoon at how cool "serious mode" Kase is, and how she comes through for Yamada, but it's totally undermined by the fact that what she's rescuing Yamada from is a problem entirely of her own making.