One possible reason could be that their different career paths put a strain on their relationship. Ron might be more focused on his Auror work, often away on dangerous missions, while Hermione is deeply involved in the Ministry's research and reform projects. The long hours and high - stress of their jobs could lead to less time for each other and growing apart.
Hermione would likely throw herself more into her work. She might become even more independent and less likely to rely on others. This could lead to her making new friends and alliances within the wizarding world who are more in tune with her new single - minded focus on her career and causes.
Maybe in some fanfictions, Ron is portrayed in a way that doesn't match Hermione's idea of him. For example, he might be made overly clumsy or insensitive, which could annoy Hermione.
One common theme is the exploration of their personalities outside of the main story. In these fanfictions, we often see a deeper look into how Ron's insecurities play out in a relationship with Hermione, and how Hermione's strong - willed nature affects them as a couple.
Another theme is loyalty. Ron's actions in these fanfictions display his loyalty to Hermione. He doesn't let others mistreat her and is ready to face any consequences to protect her.
Another reason could be that the fanfiction is full of clichés when it comes to their relationship. It always follows the same tired plotlines, and Hermione, being the intelligent and forward - thinking witch she is, is tired of seeing such unoriginal takes on their relationship.
Jealousy can also be a factor. Maybe Harry becomes jealous of Hermione's close friendship with another character, or vice versa. This could create tension and ultimately result in a break - up. In some fanfictions, Hermione's intelligence and success might overshadow Harry at times, causing him to feel insecure in the relationship.
There's also 'Ron and Hermione: A New Chapter' which focuses on a different scenario where they get together earlier than in the original series. The author does a great job of building their relationship in a more fast - paced yet believable manner. It has some really cute moments between them that fans of the pairing will enjoy.
One popular 'ron stands up for hermione fanfiction' is 'Ron's Defense'. In this story, Ron defends Hermione when she is wrongly accused in Hogwarts. It beautifully shows their friendship and Ron's loyalty.