This nearly induces a panic attack for me - I need routes, a plan, a map, a goal/end location, and a task. Aimless walking stresses me out big time!
This allows one to flaneur but still have a destination.
On vacation, one can literally eat lunch, then wander about the city until it is tea time, then repeat until dinner. Beautiful way to spend the day and explore the city.
Lots of things can be done while aimlessly walking.