I... don't entirely disagree. To me, you can basically separate the girls into two camps. Those that have interesting relationships with the MC and feel like the plot moves forward (at least tangentially) with them, and those that don't. Azraesha is fantastic and one of my favorite girls in all of the games I've played on this website. Fun, sexy, charming, and a dork with an interesting history all at the same time. Caitlyn is adorable and hilarious and has a fun relationship with the MC where they basically switch between being student and teacher. Lyriel is very tsundere with all her insecurities being projected outwards as thorns that you see slowly see be picked away. I'm keeping up with the game just for these three because I really want to see all three get happy endings.
Then you have Naomi, who despite having a lot of content, I never really feel builds all that interesting of a relationship with the MC. I don't need her to be submissive or anything, but it does feel like she's here for big muscle girl fanservice more than anything else with the way her sex scenes go. I'd be interested in learning more about her crew and how this rambuncious girl is a captain but instead I get sweaty exercise scenes. Yona and Blair have it much worse where Yona's complete doormat attitude got old fast and Blair's skepticism towards all things magical starts really stretching disbelief. But to be fair to those two, they have much less content and time to develop than Naomi and especially the first three girls.
I feel it's not a coincidence that the girls I find most interesting are the magically inclined ones. When the main setting of the game is a big magic mystery of the eponymous house in the rift, the fact that half the girls basically just shrug their shoulders whenever the main plot peeks it's head back in between the girls' storylines kinda sucks. And since with each new girl means more time in between main plot updates, the momentum the story had before slows down drastically. Which I wouldn't mind if I found the new girls as great as the first group, but I just don't.
To be more positive, the writing has been great so far so I trust that eventually these issues will be addressed eventually and that every girl can feel relevant to the scene. I just fear the introduction of another girl who can only shrug her shoulders when asked if they can help with getting everybody back to their worlds.