The author calls out render passes that take 100us, and considers this pass too fast to give a number to. Why does it matter if it's 5 render calls or 500? The

The author calls out render passes that take 100us, and considers this pass too fast to give a number to. Why does it matter if it's 5 render calls or 500? The developers clearly have plenty of work to do optimizing the other 70ms, it doesn't make sense for them to spend any time working on this.