What would be a good argument against the point that we wouldn't bother teaching fractions if calculators had always existed?

Math education is worse than religion when it comes to blind adherence to tradition. A lot of kids who learn calculus in high school should be learning statistics instead, for instance. And a lot of time in engineering school is wasted on worthless analytic techniques that should be spent on numerical methods that the student will actually use. Never mind the holy wars about how linear algebra should be taught. Compared to the ferocity of these debates, fractions seem like low-hanging fruit with few arguments in their defense.

Classroom time is limited, so we need to make every minute count.