Why are Buddhist scriptures vertical?

It is estimated that there are many photocopies and vertical editions, and there are several stages in the translation of Buddhist scriptures. At that time, both bamboo slips and Tang and Song Dynasties were written vertically. If you don't typeset and copy directly, there will be vertical and horizontal cooperation everywhere. The newly bought printed Buddhist scriptures are horizontal, so they are not absolute, which is determined by people's reading habits at that time.