And don't forget geometrical constructions with compasses and straight edges. Admittedly those were fun but I have yet to see a real world use beyond a niche purpose.
Maybe you don't usually learn to do taxes in school because they're piss easy. And if they're not, you could always try using your smartphone for something other than facebook.
It's something that actually applies to the average person's life. The average person in adulthood isn't given a parallelogram and told to find all the angles and sides.
Not everything is school is directly applicable to your life but it keeps you from walking around like an idiot not knowing what a parallelogram is and those engineers have to start somewhere so you can have your iPhones and cars. Besides, taxes are easy. Any parent can teach you in 15 mins
but that's just because I'm biased towards engineering.