[gus_massa]

For good paper you need some wood with long fibers. From https://en.wikipedia.org/wiki/Pulp_(paper)#Wood_pulp

> While in theory any tree can be used for pulp-making, coniferous trees are preferred because the cellulose fibers in the pulp of these species are longer, and therefore make stronger paper.

[exabrial]

Makes sense. Is that needed for toilet paper (which will buried anyway)

[gus_massa]

You need strong toilet paper so it doesn't break in your hand. I'm not sure for which applications strength is not important, perhaps the cardboard that protect electronic equipment inside the boxes(?).