Amazon's Vulcan Robots Now Stow Items Faster Than Humans

It appears this bot could be about 100 times simpler if they just had storage racks with smaller cubbies at the modest expense of usable storage volume. 1 item per cubbie.

That would be a huge expense. You would either waste a lot of space in each one, or have the robot waste time finding one that's the optimal size.

Generally speaking space is the most valuable commodity in a warehouse (up to a certain height).

A robot that costs 5x as much but yields 30% more usable space is a better value proposition.

Also you wouldn't be able to accommodate anything besides items that fit in that specific pick bin (what a cubbie is called in the industry), meaning you would always need a near perfect match of # of bins of a specific size to the # of products matching them. It would be a continual battle to change racking as products move in and out of the warehouse.

A more complicated robot is a better robot, in this case.