Long addition is similar to calligraphy in the sense that its deprecation would have little effect on our civilisation's ability to continue functioning as is. They also both require patience to learn. The analogy is tempting.

However, contained within the process of learning long addition is a microcosm of our mathematical praxis: useful parables about logic, pattern, deduction, notation, communication, quantity, and more. There is a great deal to be derived from its study which, by scaffolding young minds, leads to more mathematical scientists, and hence value for society. I would have great difficulty arguing the same for calligraphy.

I don't always go out walking because I have somewhere to go!