Plot and character and the novel - in Conversations with Friends

I feel like a hypocrite, having criticized some novels (e.g., The Incendiares) for too much plot and insufficient development of character and here I'm about to criticize another millennial novel - Sally Rooney's Conversations with Friends - for the opposite, but I guess the point is that the ideal novel must include and incorporate both: good narrative driven by various plot developments including conflicts resolved and protagonists coming to some kind of self-knowledge, smarter and more experienced at the end than at the outset, plus strong characters who give us access to their interior life and knowledge and perspective based on where they've come from, family background etc. (Should also have a sense of style and wit, a sense of place or mood, and perhaps a point to make or a message ...) Spoilers will follow so if you're planning to read Conversations w/ Friends suggest you stop here. Rooney's novel has so much potential and promise - a really intelligent and witty narrator and a tight cast of characters; in my first post on this book I called it a chamber play, and that characterization holds true throughout: Essentially there are only 4 characters (2 couples in a sense, everyone else is a bit player at most) who go through various episodes of breakups, reconciliations, and so forth, with most of the focus on the narrator (Frances) and her affair w/ Melissa's husband, Nick. There are many well-rendered sex scenes and extensive conversations - in person, on the phone, and via email - about every aspect of the Melissa-Nick relationship. Nick, unlike just about any guy I know, talks incessantly about his feelings for Melissa and for Frances, and is extraordinarily solicitous about her feelings; the two most frequent phrases in in this novel must be "I'm sorry" and "Are you OK?" So, OK, strong character development here and a lot of insight into the consciousness of others, particularly the narrator's. On the other hand, Rooney flirts with plot development but never succumbs: it's as if she approaches the edge of the abyss but won't take the plunge. For ex., Frances is hospitalized with a serious gynecological condition. Will she die? Is she pregnant? No, and no. Her father drinks himself to oblivion and at one point fails to answer her many calls. Has he killed himself? Died of alcohol poisoning? No, and no. Frances and Nick live in dread that Melissa and FRances's roommate/best friend/sometime lover (Bobbi) will find out about their relationship. When they do, does anything change? No, and no. I could go on - but it's a novel that ends not much beyond where it began and seldom leaves the world of this foursome (as foretold perhaps in the title). We learn a lot about these characters along the way, but there's some enervated, even claustrophobic about this tight, circumscribed scope of this narrative.