Mike Ash writes:

Pray tell, how do you avoid running into walls, falling down stairs,
getting hit by cars, etc. when you do that?

The question is one of equilibrium, not obstacle avoidance. There are no
stairs, walls, or cars in the air.

It is possible to walk competently for an indefinite period with one's eyes
closed. It is not possible to fly competently for any significant period with
eyes closed.