I really like the 1+1=3 cognitive load analogy on the cost of adding a "single" click to something. One of the most aggravating things in the last 15 years is a seemingly industry wide decision to "declutter" menus by burying even very simple, common actions 4-5 menus deep, often with icons that have no discernible clear meaning until you click around for a while and figure it out.
Why? Seriously, why?