[et-al]

That's because up until recently, the only tools users have to interact have been 2D. If 3D becomes a thing, more designers will embrace it and think of new ways to communicate ideas in that space.

Also, in a discussion about communicating efficiently over limited bandwidth, and the possibility removing web fonts, 3D spaces is in a completely opposite direction. We'd have to load vector files and texture maps so that the 3D space doesn't look like crap.

Also, there's a limit to how much input a human can process. There's a reason why certain sites have gotten more simple to restrict distractions.