One of the reasons that makes me think of Obito as a very realistic character is the person he became after experiencing heartbreak.
And I think that the people who like to throw the word "simp" at him after he cracks at the death of Rin really underestimate the pain and despair of getting your heart broken, and how badly it changes you.
Have you ever experienced a heartbreak SO BAD that the trauma made you abandon the old ideals that you once believed in, such as your views on friendships, love, society, or whatever?
Some may recover and in fact, learn to see things in a more positive way after an experience like that, where they can take the pain as a lesson to be learned, and move forward. But some end up shutting out, become meaner, and just keep a really hard wall around them so that they don't feel the same pain again. Some have their mental health so f*cked by the experience that they end up needing to get help.
Heartbreak and despair does that. It's a f*cking painful, and brutal experience.
In Obito's case, sure, for the sake of the plot and fictional purposes, he becomes insane and psychotic, and sadistic and heartless, but realistically, he was drowning in so much despair that he couldn't see the good in the world any further. He already hated the rules and ways of the shinobi world, but he held ideals and values that made him go on, before Rin died by the hands of Kakashi.
And Rin was someone incredibly important to him - in every way, not just romantically. His words "she was my only light" isn't something cheesy, it's because she was someone who made him feel like he had a purpose in a cruel world - his skills were shit, he was below average, and if Rin wasn't around, he'd only be put down by everyone. She was the only one motivating him to continue reaching for a goal that everyone thought he could never reach.
Now, imagine losing someone like that. The heartbreak and pain of that will change the way you see things, too. No longer will you believe in the good of this world. No longer will you want to create connections with anyone. No longer will you believe that there is hope, all that you can think of is how everything is just absolutely temporary and meaningless, and how nothing ever feels true.
You might say Kakashi went through so much shit as well, but the way it changed him is different from the way it changed Obito. The experience of heartbreak and pain may create a good change, or a bad change. In Obito's case, it became a bad change.












