Simplicity. There is, of course, some duplication of structure and material inherent in a modular system like this but the flexibility warrants it, I think. Here we have just a few pieces, the only essential one being the 16x16x16" cube, a 'no-waste' dimension based on US plywood size of 48x96". Base and top are optional, attachment blocks are made into a visual contributor (?). Inside face countersinks not shown!
[image: PA7H_cubeshelving-1.JPG]