Long division perhaps does teach you how to follow a complex algorithm by hand, but it's not at all necessary for the math curriculum at any stage from K-12 up

Long division perhaps does teach you how to follow a complex algorithm by hand, but it's not at all necessary for the math curriculum at any stage from K-12 up to university. It's somewhat out of fashion because a good sense of number is just as useful for dividing by hand, and more useful for understanding what's going on (plus, you do now always have a calculator in your pocket).