Why are most of the great calligraphers in ancient times great officials?

First, in addition to the founding heroes, there are some military commanders with low educational level and some aristocratic monopolies before the Sui Dynasty. In ancient times, it can be said that people who could read and write could not have poor family conditions, while the great calligraphers in ancient times were actually scholars, but calligraphy was well written among scholars. In ancient times, practicing calligraphy was also a big expense, and it was impossible to persist without certain financial resources. So it's usually a government official. In ancient times, it may be said that some great calligraphers later became more interested in calligraphy than in imperial examinations. However, if you are not an official, it can be said that it is impossible for your family to train you, as well as your parents' expectations, the influence of the environment and your own future, such as getting married and buying Four Treasures of the Study, which is very expensive and has no certain social status.