i think that’s kind of the point actually.
catra and adora are both infuriated by how shadow weaver seems to have joined the good guys without suffering any serious consequences for the abuse she inflicted on them, on top of what she did to the rebellion as a whole. she’s essentially “forgiven” because her magic is useful for the rebellion, not because she’s atoned or expressed remorse or done anything resembling a genuine attempt at redemption (if that was even possible for someone as power-hungry and cruel as her). it’s completely unfair and messed up, which the narrative seems to recognize.
however, glimmer didn’t always recognize it, which was a major factor in her and adora’s deteriorating relationship. glimmer went from being protective of adora when adora confronted shadow weaver to mocking adora for no longer being shadow weaver’s “favorite” (even though the latter was for show, DT themselves pointed out that it seemed based on genuine feelings).
sometimes abusers do get away with it, because they’re just that good at manipulation. that said, shadow weaver’s plan to control glimmer failed, so while she’s still “free”, at least she didn’t get everything that she wanted.
it’s very frustrating to watch, largely because it’s painfully realistic. master manipulators/abusers like shadow weaver often “win” or “get away with it” by moving onto the next target, and it’s horrible.