The load-bearing principle of origami is to disperse or indirectly offset external pressure.
It's like a piece of paper. When the paper is folded, it is forced into multiple points, and the final shape cancels out the external pressure.
A seemingly simple piece of paper or multiple pieces of paper will be greatly released after combination, and the damage forms of the bridge are various. Therefore, it is necessary to fold to show the result of exerting force, which also reflects the combination of structure and mechanics.
Paper does have a lot of capacity when folded, and it depends on the stress of the paper fibers. After the paper is folded into a corresponding shape, each slope will have a corresponding load bearing capacity, and naturally can withstand a greater force.
You can also get a few pieces of paper to experiment with. You can get three pieces of paper, fold the paper into cuboids, cylinders, and triangular prisms, and tape them together. Then you can put the book on the three sheets and see which one has more carrying capacity. In fact, the carrying capacity of paper is mainly determined by the number of faces. The cylinder has a higher carrying capacity than the cylinder.