Why is school such a waste of time?

It could be that many schools are spending most of their resources teaching students subjects dominated by such lessons as "manipulating an object (often a ball) while abiding by arbitrary rules to achieve victory according to said arbitrary rules," aka sports. Seriously. I'm not against sports for fitness or anything like that, but schools are centered around sports. They should come up with a new term summarizing "an academy in which students obtain skills that will allow them to mutually help society in an intellectual way," and the term "school" should mean what it happens to be now: "an academy in which students obtain the ability to satisfy arbitrary rules in an attempt to do absolutely nothing to help society."