I cannot speak for everyone, but my elementary school had analog clocks (which kids learned to read) while maintaining recess, art, music and gym.

Having taught math to children, analog clocks are a great way to learn and apply fractions. I suspect that children's inability to read analog clocks tracks pretty well with their abysmal math skills, like fractions.

So maybe we don't "add" analog clocks to the school curriculum, but we instead replace some nonsense with analog clocks and fractions.