@Nep I don't think it has anything to do with what you mention. (isekai, harem, tsundere, or 'cute girl doing cute things')
It won't be adapted until they can make it politically correct.
If you notice, even on mangadex, the voting/rating system often has a men vs women vibe as women will downvote anything they feel is pro men, and men will down vote anything that is pro women.
This manga in particular gives off a historical vibe where some women are treated as property while there being a different status for certain types of women (in terms of power) and some men are powerful while other men are eunuchs.
This causes a "balance" of sorts that causes the readers on mangadex to vote as there is some sense of equality, hence the high rating.
Basically to summarize what I am trying to say...
This manga would be hard to adapt in the current global political climate.
I would not be surprised if it blocked by those on the left.
Also, the tone of the story requires a relatively mature mind. The true target audience will be adults, or younger people who have the patience and understanding for such a story.
It's a shame, but it is what it is.
Also I should add, right now with the "simp" culture, it might cause "ideas" as basically this chapter in particular shows a "simp" being able to literally "buy" a woman.
That's why many simps/beta-orbiters/white-knights are giving random ethots all this money and attention, because on an instinctual level that was the norm (in the past) to attain a woman.
If people start reminiscing of the simpler times of the past, the current ruling parties (specifically the left) would not like that idea being reinvigorated in our current times.