Suffering is not the main ingredient for character development.
The easiest way to write complex characters is to break them. Not right in front of the viewer, but sometime in their past. The author can kill their parents, destroy their city, make them the target of bullies, or find another way to make them miserable and force them to grow into who they are through overcoming this drama. But is it really necessary?
Death in anime and manga became a cheap trick to supposedly give depth to characters long before it was introduced to the mass media through Game of Thrones, and a sad backstory with various levels of sadness marched along with it. And as time passed by, this trope first became boring, and then irritating.
Surprise, some characters can be compelling and real and fully fleshed out without any kind of sad drama in their past lives! Look at the cast of Mob Psycho 100: the main character, Kageyama Shigeo, has a full, loving family, he had friends in his childhood, but that doesn't stop him from becoming one of the best shonen protagonists of the past decade (and disturbingly powerful, too). His teacher, Reigen Arataka, became a conniving swindler not because he was hurt sometime before the events of the show, but because he didn't know what to do with his life and he just went along with something that took less effort (and ended up scoring quite high in the DILF and Sexyman polls last year).
One of the main hits of the 2022 Fall Season, Bocchi The Rock, features a girl who hasn't had any traumatic events that have made her socially anxious — no, she's just a girl who tries to adapt to the world we currently live in. Does it make her less relatable and compelling? Does it make us love her any less? On the contrary: it makes her even more grounded and realistic.
Tragic past paves the highway into the souls of empathetic viewers, but this trope is so overused that it stops working even for those who take the pain of 2D characters close to their hearts. And as viewers encounter it time and time again, they grow less susceptible to it, prompting the authors to crank up the level of ruthlessness to elicit at least some emotional response. This results in the average level of violence in modern anime series being quite high as opposed to the previous decade throughout all genres.
But do we need to invite more pain into our lives?