I mean... Couldn't they be? Destruction of property is still destruction of property.
No, arresting the kids is outta the question as it would be a public embarrassment for all parties involved, which is unlikely in Japan or developed Asian culture about saving face (especially among the adults)... until some extreme threshold is reached.
Caning/Corporal punishment of children was banned in Japan back in 2019-2020 so bad behaviors aren't immediately corrected or quashed by responsible adults. Failure in public education is systemic, but most people won't ever realize it until either from parenting or find random kids running around doing all sorts of unrestrained stupid shi* and vandalism.
So now the best option for most adults is to let the kids "grow up" by FAFO amongst their peers (for better or worse). Takayanagi sensei along with the principal and vice principal being competent and responsible adults was unexpected, if not refreshing. I don't expect GTO-like teacher(s) given the premise of the manga thus far, but it'll be interesting to see how the kids grow from here on out.