Collapsible Docs Navigation

Don't want to be a naysayer, but the Cards approach to Docs means: 1) you can't see all the Doc categories without scrolling; 2) any time you want to move between categories, you now have to click out of a category back to the entire collection of Cards. I don't understand this approach.

Same as Threads having collapsible "Everyone" and "Messages" sections, I would love to see each Doc category as a collapsible section in the left-hand menu, where you can see many more categories at a time (than with cards), and the navigation between categories is always showing, rather than having to go back to a central docs hub for that navigation.