Even though in the end it featured her growth beyond needing a forced institution to keep her in such a relationship, yeah the ending felt pretty lukewarm but that's fine. I wouldn't call this a bad way to end things or a great one either. I don't believe this series deserves a 6.5 rating, maybe a 7.5-ish as strong series who end with a lackluster ending usually end up at. Either way this series made me binge 187 chapters in 2 days and I was constantly captivated by each scene and chapter.
My one gripe? I think the way they handled filler chapters in this gave an unrealistic form of character growth that the characters just weren't capable of in the main story, at least to the reader's perspective.
TLDR: Worth the read. Not a great ending but over-all a pretty well-written series with character development that'll keep you glued to your seat!