Why must the publication of ancient books be printed in traditional Chinese characters and arranged vertically?

In the process of ancient books from the traditional vertical arrangement of photocopying to the simplified horizontal arrangement of mass reading, the accuracy of information is declining. Among them, the error may be caused by the imperfection of copying technology or some "human errors" of proofreaders. Of course, the former is inevitable, while the latter should be reduced as much as possible.

For example, there was a poet named Huang Jingren in the Qing Dynasty. He wrote a set of poems "Feeling Old", which is very famous. There are four poems * * *, and only four are selected here:

Since then, the sound is quiet, and the spring mountains are like smoke. Tears add to Wuyuan's rainy night, and I wish I could not let the postal kiosk sleep all night. There is a robin saying goodbye and talking about the golden harp. He sometimes takes off his stool slightly, but he only feels sorry for himself.

If you already know some metrical patterns, it should be easy to see that the whole poem, as seven rhymes, only has the word bird, and the bird should be flat. Then we can guess that there is a great possibility of corruption here.