I do not approve of how FMC rejected MC character growth has something entirely bad or bad enough to break things over with him, he never did "anything wrong", as he grew in fame he grew in many positive ways and to be honest him becoming distant as an editor or any other profession it's actually really normal if we take into account how successful he became.
If your loved one becomes successful in his dream job but at the same time grows distant due to the same success and the high demand of time required to maintain this success I believe this is a valid concern, many successful people suffer from this.
But the way you go about it it's thru communication as a couple you are supposed to express any concern you might have about the direction the relationship might be heading, she needed to express her feeling regarding his change on how it was impacting their relationship, and give him the opportunity to correct how distant he had become with her, and for them to be able to amend their relationship.
But what FMC did instead was to observe in silence while her resentment grew just to eventually abandoned the entire relationship and gave it up as a lost cause.
If she had expressed her feelings and concerns and he had refuse to change by all means yeah dump him, but she never gave him that opportunity.
But in exchange in ch. 36, MC had to abandon any growth good or bad because like I said he also grew in positive ways, just to revert back to his old self in order to win FMC back only after he begged over 200 times, I mean WTF.
And from ch. 37-47 we have this pile of garbage of a story that has no direction or purpose other that to keep dragging MC character thru the ground, I'm mean really this is all there is to it there is not real story here.