Honestly OP isn’t wrong in that most students won’t ever use the math they learn in school. The small portion that attend university and study physical sciences/math/engineering might, but the rest…doubtful.
With that said, learning calculus in high school should be thought of in the same vein as reading Dostoyevsky or learning 1500s European history or doing titrations in introductory chemistry. You don’t do it to gain specific knowledge; you do it to develop critical thinking skills and a broad knowledge base. If we go with the logic of “only teach what kids will actually use day to day” we’d be left replacing high schools with vocational trade schools.
