[vacri]

Well, the one thing you've missed in all the items is waste removal, which is just as important as nutrient distribution. Also, we absorb more from our food than just energy. And even then, you caveat your answers with "but these are simplified and incomplete".

Then compare to the article, a bit of long-form journalism rather than throw-away summary lines, which opens with the statement that there's one crucial reason for sleep and we don't know it.