I don't know, it works for me.

Using Sidebery panes and treestyle tabs makes it really easy to organize your tabs, I have a tree with all my tasks with relevant documentation or subtasks under each task, and I have a separate panes with all the documentation I refer constantly at the top and everything I'm reading right now at the bottom. I definitely have a lot of tabs I opened to read and never closed, but that doesn't matter since everything is arranged in an approximation of a 2D space, I still know where to look for something specific. I'm sure you feel this is weird because you've never used a tree-style tab manager, but personally I can't go back to a regular browsing setup.