Sakura might grow tired of Sasuke's cold and distant behavior. In fanfiction, she could realize that she's been trying too hard to hold on to a relationship where she's not getting the love and attention she deserves. Maybe she meets someone else who shows her more care and respect, which makes her consider breaking up with Sasuke.
One possible reason could be Sasuke's continued obsession with revenge. His single - minded pursuit of power and vengeance might make Sakura feel neglected and unloved in the relationship. For example, he often goes off on long and dangerous missions alone, leaving Sakura behind worried sick. Another reason could be a fundamental difference in their values. Sakura values life and healing, while Sasuke has been more focused on destruction in his quest for revenge.
One possible reason could be that Sakura realizes Sasuke is too consumed by his revenge and she can't keep waiting for him to change. She might see that he is constantly putting her in a secondary position and she decides she deserves better. For example, Sasuke has left the village multiple times, leaving Sakura heartbroken each time.
In some fanfictions, Sasuke could be under the influence of some dark power or curse. This power might compel him to kidnap Sakura. For example, a dark entity might want to use Sakura's abilities or her connection to Sasuke for its own evil purposes, and Sasuke, being unable to fully control himself, follows its commands.
One possible reason could be Sasuke's pursuit of power. In many fanfictions, his thirst for greater strength might lead him to leave Sakura behind as he embarks on a solo journey to train in more dangerous and secluded places. He may feel that his goals are too dangerous for her to be involved with.
One possible reason could be a lack of communication. If Sasuke is always away on his missions and doesn't share his thoughts and feelings with Sakura, it can create a rift. Another reason might be differences in their long - term goals. For example, Sakura may want a more stable family life, while Sasuke is still too focused on his pursuit of power or justice in the shinobi world.
One possible reason could be that Sasuke is frustrated with Sakura constantly trying to get close to him when he's focused on his revenge. He might yell at her to keep her away and not interfere with his plans.
One possible reason could be Sasuke's continuous absence. He is often away on missions, leaving Sakura feeling lonely and neglected. In fanfiction, this could be exaggerated to a point where she can't take it anymore.
One possible reason could be a misunderstanding. Maybe Sasuke has been misled to think Sakura is a threat to him or his goals at that moment. In the Naruto universe, Sasuke has often been on a solitary path filled with suspicion. He might tie her up to keep her from interfering with something he's about to do. Another aspect could be related to some kind of test. He may want to see how Sakura will react in such a difficult situation to gauge her growth as a ninja. It could also be a part of a plan to protect her from something more dangerous, by restraining her movement in a way that he believes is the best for her safety, using the snakes as a means to immobilize her as he is known for his snake - like jutsu.
One reason could be a misunderstanding. Maybe Mal overheard something Ben said that she misinterpreted. For example, if he was talking about some political decision for Auradon that she thought was about her personally.
In fanfiction, Sasuke might snap at Sakura due to miscommunication. Sakura could be expressing her concern for him in a way that he misinterprets. For instance, if she tells him not to go on a dangerous mission and he thinks she is trying to control him instead of just caring about his safety. Another factor could be the influence of external forces. Maybe there are other characters or events that put him in a bad mood, and Sakura just happens to be there at the wrong time, so he snaps at her.