This is a comment in addition to that by TheHouseAlwaysWins because I am 100% in agreement with that assessment and could not have repeated it better.
Is this the best story ever? No.
Is it well executed? Absolutely.
While I mourn the lack of the Yuri route (or even a more fleshed out trio route which i would have preferred), I still loved the execution. Don't read this for the romance or the world building. It's all character development. This isn't a grand love story. It's a story of survival.
Arth and Sasha end up in a happy marriage because they love each other, not to the point of obsession or greed or vanity or heart surging pain. They love each other by being each other's support and constant person. And i think that is beautiful. Now if only Rebecca could have gotten in on that a bit more would I be fully satisfied.
We see love in so many different forms throughout this story that it becomes clear that love isn't actually inherently good when wielded selfishly.
Other comments refer to the lack of an actual villain, and it's true that there isn't a singular individual that embodies evil. How the author seems to characterize "evil" is through selfishness at the expense of others. Even those characters that are evil in this novel know love, but their choices to be selfish and cause suffering too those around them is what makes their acts "evil." Is actually a surprising thing to see explored in such a short and simple story. Three author convinced me to buy into the relationships and their struggles even when minor.
For example: the royal family, Lilith's mother & father, the crown princess, and even other women who abuse Sasha. They all felt some type of love, but their selfish choices harmed others maliciously and negligently. And the author clearly characterizes these as evil acts. In contrast, the author characterizes Arth's plans and Payne's acts in support of Lilith as just results borne of love, so those are righteous and good. As a reader, you can agree or disagree, but to seen it shown like that demonstrated great execution of the messaging.
TLDR: relatively simple little story of revenge, justice, and love (not always romantic love) in a patriarchal historical-esque society of nobles starring a transmigrator. A cute series that I would recommend and would read again.