Kuzumi is basically the dead fish girl in a relationship. Erika definitely deserves much better. I don't like what the mangaka is trying to convey here. Communication needs to happen on both ends and you must absolutely understand each other as best as you can. Hopefully, there aren't too many impressionable youngins reading this and think it's ok for a relationship to be one sided.
On that note, I think https://mangadex.org/title/14162/7-jikanme-no-note does a great job of showing what a healthy relationship, especially for a high school couple, should be (talking about main couple). The latest chapter is basically the anti-thesis of this manga and it's a great chapter, especially if you've read tons of romcoms where the main driver of the plots are miscommunication.