alt Hacker Newsnot picking on you, specifically, but i wonder how many people could roughly draw a cardboard box template correctly. It is an easier object than a bicycle, which people routinely have issues drawing, too.
generally, there's not "missing pieces" in a cardboard box.
Fair, that template resolves to a box but it's missing stuff like tabs to make the bottom properly stick ; and it's probably not optimal in its use of cardboard. Also it was design in a minute in draw.io to make a stranger on the internet chuckle, so lots of constraints to fulfill.