Sure, there is some hassle with multiple screens. However, you can easily buy office monitors which are, in effect, two full-sized portrait pages (A4 or letter) next to each other.
So a natural use case is to edit a full page document on one side, and have another full page document next to it that you can read or reference.
So a natural use case is to edit a full page document on one side, and have another full page document next to it that you can read or reference.