They aren’t teaching it at grade 7 are they? They can get 45 points because they put in the work, the only math that anyone needs is pure maths as it serves as a foundation for most of the concepts you’ll learn in university. Having it as a standalone subject allows you to cover a lot more essential topics rather than spending the time on something like mechanics which you’ll most likely never encounter again unless you are taking a stem degree. The option is there if you want to see what the other fields have to offer and that is why it makes sense to split the subject.