Following the GPS gets you there. Knowing the streets gets you there when the signal drops.

Directions given one turn at a time get you to the address without building a map in your head. That works perfectly until the moment it does not, and then you are standing somewhere with no idea which way anything is. The same shape shows up everywhere. The tool gets the task done, and understanding is what carries you when the tool is gone.

Try one familiar trip this week without the voice telling you where to turn. Look at the route first, notice two or three landmarks, then go. Getting slightly lost on a road you know is a cheap way to learn it.