it's not really out of place. it is mentioned that it was an experimental school, and students found it really easy to enjoy school life thanks to troia. they found it fun to have their school life to be 'gamified' so they really have no real reasons to transfer to another school. there are of course those who are abusing the app, but perhaps their mindset is that as long as they're not involved, it's fine?
...and high school is also the age of students where social status matters the most, that's probably why bullying is still prevalent, but even worse now that an app has ranked them all down. as a result, i guess the students were encouraged to do missions for ranking up to avoid the worst case scenario.
at least, that's what i can gather from these past four chapters. ╮( ̄▽ ̄)╭

This is an interesting idea, but I don't get what's the stakes for the students. If their score is low then they'll get expelled? And people bully them if their scores are low?
This just seems like stuff that happens on its own without the phone app at all. If I were them I would just go to another school. All this artificial tension with no real stakes is making the whole phone app idea seem out of place.
That or I'm too used to very high and horrible stakes like extreme debt or death . Each to their own I guess.