Here are two mains power sockets from around our home. One is a standard grounded 220V socket. The second is obviously much better: in the same space, for the same trouble, it takes two plugs! In the USA this is of course standard practice; all wall socket panels have two sockets. Here, though, this is less common, perhaps because our plugs are larger. So – isn’t that twin socket neat?
Well, it would have been, if the designer had been thinking. You can see the problem in the next photo: most grounded mains plugs have the cable coming out the side – and this means the second socket in this panel is obstructed by this cable. All it would take to fix this is to build the panel the other way around, with the ground connections on the outside rather than facing the center, or better yet, place the two plugs side by side with the cables going down towards the floor. Cost and complexity of production would have been identical; usefulness would have doubled.