More spatial memory/association(i.e. left page/right page) could boost memory and understanding.

This is a very very essential feature for many since it's important to have a better sense of where some information is located, say, three pages ago on the left, or two pages ahead on the right, instead of somewhere in the middle of one single long scroll. Using two-page scrolling is like doubling the bandwidth of our "brain RAM" in sorting out the ideas located on different spots of the book.

The lack of this is a reason why digital reading is worse than real books. (reference: https://www.scientificamerican.com/article/the-reading-brain-in-the-digital-age-why-paper-still-beats-screens/ )