Maybe dont break the fucking law over and over again.

Watch houses are only really considered acceptable for adults and a maximum of 24 hours.

A night in a cell can help an adult - it's a real wakeup call and a forced opportunity to sit and think about what you just did.

Kids often haven't learned how to do that yet (especially if they haven't had a good upbringing) and by adding one more traumatic experience to an already long list in their short life is just making things worse for everyone, including the victims of the crime. Compounding that - being kids they need supervision and there's often nowhere else available - you can release an adult and let them go out in the world on their own with a bit of basic help (this is where you can find food, shelter, work, etc). But a child can't be released, they have to do a hand off to a trusted adult. And when one can't be found the cops have no choice but to keep them in locked up - sometimes for over a month. Even for an adult a month in a watch house would be extremely damaging, let alone a child (especially one who has other mental health issues which is very often the case with anyone who behaves badly in society).

Keep in mind every single one of these kids is legally innocent (since they haven't been to court yet). The kids need adults to show and teach them how to live a successful and happy life and our society is failing to provide that. The kids aren't the ones to blame for that.