What does it mean that accessibility of frequently used items?

Things you use often should be within arms reach.

Example: A software engineer keeps their terminal, editor, and browser in a three-monitor layout with keyboard shortcuts to switch between them in under 200 milliseconds. A writer who reaches for a notebook six times per session moves it from the shelf to the desk edge. The items did not change — their position did — and the friction cost dropped from five seconds to zero.

Try this: Audit your workspace right now. List the five physical objects and five digital tools you reach for most often during a work session. For each, time how long it takes to access — seconds for physical objects, clicks or keystrokes for digital ones. Rearrange so every item on your top-five list is reachable in under two seconds or two keystrokes. Repeat the timing after rearranging.