Carol's come a long way--I remember when she was introduced, cursed (so it was back then) with the Temptress job, hopeless as a result--you could see it in her eyes. Now, she radiates happiness, and you can see purpose in her mannerisms, posture, and eyes. Aside from that, she used to wear ugly pantyhose (but was still cute in her way), now she wears thighhighs, and has a waist belt. I'm not into flat girls, but that notwithstanding, Carol's definitely proving she's wife material, like Haru has. A good wife makes herself useful, and both of them do in multiple ways.
Unlike Mareena. She's such a +1, it's painfully obvious--even Ichinojou alluded to it more than once in this chapter.
That said, lots of people REALLY need to get over slavery. The people triggered over it are only so because they're trying to virtue signal; they do it also for the main people who cry about slavery (aside from from the Tumblrinas) in this day and age--who all do so in a Western world where it is outlawed across the board, and has been for at least a century. Both those people and the Tumblrinas do it for power, because controlling someone's tongue is one of the ways by which a vicious individual can gain power that person.
What's more, what slavery happened in the past happened because it was the name of the game back then. Throughout human history, humans also subscribed to and lived by the rule that comes from nature itself: the strong rule, and the weak are dominated. Everyone capable did this, without exception--that includes the ancestors of the aforementioned "people". It's the hallmark of a civilization that isn't societally advanced, one that is still relatively primitive.
Just like in this story's setting.
Perhaps the Tumblrinas who keep griping about slavery in every single manga it appears should grasp and remember the above facts and the fact that it's just a story. Like they say, it's 2020, not the 1700s or before. No well-adjusted person actually cares that much about slavery that happens in a story and only there.