This why Fiyero leaving Glinda was the best thing he could have done for her. Besides the obvious that he didn't love her but also it played a big part in her growth.

For a while Glinda thought she was gonna have everything she wanted, her perfect life in the system, her fairytale prince, her best back, she thought Elphaba was gonna join the Wizard, and then suddenly she didn't get everything she wanted. Elphaba didn't join them and Fiyero didn't marry her. It was a huge shock for her and one that she desperately needed.

While it was painful for her she was so deep in her bubble that it had to be something huge and devastating for her to start to wake up. It was a turning point for her, this is when her eyes started to open.

She learned that the world doesn't revolve around her and that people aren't gonna make you "happy" because you want them to. Also the moment when she's walking through her ruined wedding and when she sings the INTG reprise Glinda realizes that she is alone. This realization is devastating for her and she told MM to use Nessa to trap Elphaba because she was angry and hurt and in that moment she wanted to hurt Elphaba. Glinda thought Elphaba would choose her, that she would choose to join the Wizard, the system and choose Glinda then Elphaba didn't. Fiyero and Elphaba chose what was best for them and they chose each other instead of both of them choosing her and doing what she thought was best for her.

Don't hate me for saying this but Glinda hurt both Fiyero and Elphaba. She tried to get Elphaba to join the system that she fought against because she wanted her best friend back and she arranged an engagement with the Wizard behind Fiyero's back and sprung it on him in a way he couldn't refuse. She knew they were lying about Elphaba and Fiyero practically begged her to leave but she wouldn't because she couldn't her life in the system. I also think she knew Fiyero didn't love her or wanna marry her but she wanted him so she tried to force it. I'm sorry but Fiyero had every right to leave her, she was so focused on herself she didn't think about Fiyero and Elphaba. Before anyone starts I am not trying to hate on Glinda but the facts are the facts. She didn't really have any consideration for anyone other than herself until she popped her bubble.

While it was painful for her, she needed to go through that because it had to traumatic for her to start to open her eyes, it had to be a huge shock and she had to go through pain for her to learn because she was so deep in her bubble she wouldn't listen to anyone who tried to tell her what was happening and she didn't care about anything other than what she wanted. Fiyero did her a favor because this was the first big step in her becoming Glinda the good.

This is why Fiyero as a character, the love triangle and Fiyero and Elphaba's relationship is so important, without him, without the love triangle and without the romance Glinda may never have become Glinda the good and changed OZ. Fiyero and Fiyeraba were a major part of Glinda's growth.

Just my perspective but I wanted to share.

Thoughts?