That can definitely play a role later on in the story based on the overall message but as it currently stands, it isn't the main focus. That's also why alot of the bullying done by these other characters has been, for the most part, small as it is easier to move past your bad actions/decisions if their significance is small. But the manga also shows how even small actions can have a big impact, both negatively (how she was a social outcast but for the most part seems to mainly have been exclusionary rather than straight up dumbtacks on seat, flower on desk kinda thing we are way to used to seeing in these sorts of stories) and positively (learning to forgive yourself, make amends, and be better for it).
Where as you can make the argument it's unrealistic for so many of the bullies to basically move past their hang ups, it's also unrealistic to have too many bullies in a story where what they basically do is straight up criminal. Don't get me wrong, those type of people do exist but considering how often they appear in Manga, you assumed Japanese Highschool is a war zone.
This is a nice change of pace so I am all for it.
