There's a bit of a pattern in Act III with the companions becoming less "people" and more "video game characters" - collections of pixels we're not really supposed to get attached to or take seriously. Possibly just another symptom of Larian running out of time to polish things.
Couldn't have put it better myself. Honestly, entire act 3 is just a mess. The only thing that is polished in act 3 is House of Hope.
Halsin turns into an atrocity, we get an obligatory brothel orgy scene (using companions with backstories least suited for it), Mizora is forced on you and does nothing apart from standing there propositioning you for sex, your companions don't care whatever you do with Haarlep, and the game ends with an abuse victim running away in pain while the rest of the party make fun of him.
