The only definition that compares two things for better (comparison must be made for this sort of question)-
"Improve on or surpass (an existing or previous level or achievement)"
~Google result for "better definition"
Holidays don't tend to achieve much- If you devote them to working on a project, then certainly holidays are better than school, as large chunks of school activities are complete wastes of time, whereas personal projects have an end result that to you at least is certainly better.
However, almost every kid just spends it relaxing, or travelling. While certainly helpful in that it lets the brain recharge, school certainly achieves more than holidays, thus rendering school superior.
1. Holidays are boring when school is exciting! At school you get to see your friends ！ Lots of children can't wait until the holidays but soon they are just as desperate to go back to school because they are really bored ！
2.Don't you forget stuff in the holidays ? Well kids do too, usually school work too. Working hard at school is great but practicing at home in holidays is even better.
3.Friends . . . Even if you go on play-dates you can't see them all day. At school they will be there to help and support you when you need it .
4.As a parent they don't have time for kids, even if parents have time they don't use it on kids, they probably just send them off to o something !