For what? It isn't useful for teenagers who are trying to get laid and be cool, at all. It also isn't useful for what 99% of humans end up doing, unless by math you mean basic arithmetic, enough to add and subtract on your 'smart' phone.

Math isn't useful. People who are amazing at math and are interested in it - they can be useful, but mostly not.

What they don't teach in school is how the real world works, because it is fucking outrageous. What they teach is how to go be a cog in a machine, run by idiots.

They don't teach it by telling you, they teach it by making you sit still, listen and do arbitrary, idiotic tasks for 12 years.

Sure they teach you a thing or two along the way, but anyone would learn more from doing anything else they were interested in for 12 years.

That's the dirty little secret. If you let people do what they are interested in, they'll learn math, programming, exercise, health, whatever, because it'll be necessary to achieve their goals. But you can't make people who've had a taste of achieving their goals slave away their whole life to help some idiot achieve theirs. Plus most parents are fearful idiots who never treat children like human beings, they treat them like their personal pet project whose goal is to line up with society's idea of success. Pathetic. Oh well, that's people for you :)