A tube of toothpaste is such a simple thing! It has a throat with a lid at the top and a flattened and sealed lower portion.

The tube is a remarkable thing compared to vials and jars because it is much more convenient to extract the contents from it. However, the tube has an serious disadvantage because it lies and occupies much space on a shelf.

One inventor proposed to attach a hook to the lower portion of the tube so that it could be suspended. Another one wanted to make the tube bottom flat so that it could stand vertically on a shelf. This is convenient so long as the tube is full. Then the tube either looses stability (the center of gravity concentrates at the top together with the contents) or you should press the contents from the bottom to the throat each time you use the tube.
Inventors took a long time to notice an obvious solution – to do vice versa – to put the tube not on the bottom (like a bottle) but upside down. Indeed, why not to use this resource by making the lid flat and wide? In addition to saving the space, this facilitates extraction of the contents because toothpaste is naturally concentrated near the throat by gravity.

The tube construction has not become more complicated while the slightly increased material consumption will pay due to the additional space on a shelf and increased demand.
This solution is quite habitual at present and is even used for packing other products. Bottles for various toiletries (such as shampoo) now are also provided with wide flat lids, which allows the contents to concentrate near the exit.