I actually learned how to vote in my government class and learned some of the basics of how to do my taxes in econ class. That's all due to a few outstanding teachers though. Others who had different teachers learned about supply and demand curves or whatever those things are. But, yeah, these things should be standard somewhere in your education just like learning the "facts of life" are.
But I also think learning math and science are important. I come across dozens of people every week in my job who don't know a thing about math. Like, they have to have a calculator to multiply two numbers together. I think we need to keep as many subjects available as possible so that students can have as many options open to them as possible. If students only learned "the things they'll use in life" then they'll never become scientists or anything like that. We'd be limiting their possibilities.