Writing requires a certain literary accomplishment. Is this sentence correct?

Wrong.

Children who have a lot of mathematics and calligraphy have no literary accomplishment. Shouldn't they learn calligraphy?

Calligraphy is a skill, it is difficult to get started, few people can stick to it, that's all, so it is deified by some people.

I have studied calligraphy for a long time, and it is really not easy.

Sometimes you need to look at the theory of classical Chinese calligraphy. You'd better have a little foundation in this respect, which will help you improve your level. However, it is simply wrong to say that practicing calligraphy has a certain literary accomplishment.

Taken out of context, extreme remarks are obviously problematic.