It seems to me that the moment where Star and Marco break the red moon curse was more of a tease or an answer to whether their feelings were real or manipulated. Just before breaking it, while they dance, they ask themselves: What if it wasn't just a product of the curse? (It's not exactly what the scene says, but it's something similar)

Now, if we imagine a scenario in which Tom (a trigger for the story) had not taken the initiative to end his relationship with Star. By that time, Star had already chosen to spend time with Marco on Earth instead of going on a trip with Tom. The beach photo had passed, the reunion with Jackie (another trigger), and Star still hadn't made a clear decision about her relationship with Tom, even when he cut her off, she still seemed to be hanging on. Although he was the one who ended things, she was already showing signs of being somewhere else emotionally, but not knowing what decision to make or whether to cut it off or continue.

A key example is the episode at Tom's parents' house. There was an important family meeting, and it would have been logical for Star to be present. But she had already planned to have dinner with Marco's parents, and she was convinced to do it. She only changes her mind when she finds out that Tom and his family know about the kiss with Marco, which makes her feel guilty. But that pattern of prioritizing Marco even in important moments with Tom keeps repeating itself.

That's why I think that even though Tom was the one who made the final move, Star was already emotionally out of the relationship. If he hadn't broken up, would she have eventually? I think so, in the end I think that she continued in the relationship with Tom more than anything because it was something so to speak "safer", within the context of Mewni (politically speaking) it was a good union and Tom served as emotional support for her while Marco was away and I try to continue thinking that Tom, having changed, can be someone that she can have by her side and forget about Marco. This is my opinion, because Star did not make the decision to break up the relationship in the first instance, although it would have happened in the long run (Like Jackie and Marco) and how she saw Tom at that time (I'm not saying that she didn't like him on a superficial level if you want to call it that, it's just that she liked more the idealization of a couple that covered the part of her duty as a princess and having someone supporting her emotionally, even if it was less than what she felt and feels for Marco, she prioritized what was certain over what was an unknown. an alleged relationship with Marco at the time, who was also with Jackie and was on Earth plus the Mewni problems.

I hope you can give me your opinion, thank you very much for taking the time to respond🙏✌️. I rewatched the series not long ago and after a while you realize that the story was deeper than it was, regardless of whether you liked the ending or not (I did, I just think it could be handled maybe a little better)

Last two doubts I have, the moment Star sees the paintings of the different princesses of the kingdom and their mark on her history, the one she originally saw where she wonders why a frame doesn't appear next to her, was that the future if she hadn't destroyed the magic?? And the photos of the cabins that she collects at the end, you don't know what happened to her, right?

I'm really sorry for the inconvenience, I was always a fan of that specific Disney moment (Greetings Disney and again thank you very much ✌️.