It's difficult to wear some ball bondage/stretching gear, like a parachute stretcher, while dressed. In part, gravity plays a role, so clothing, at least street clothing would interfere.
Aside from the erotic, aesthetic, visual aspect, stretchers can increase the elasticity of the scrotum and connective tissues. Done properly, it is a pleasurable sensation, and can, over time, increase one's "hang."
Most of the time, stretchers are "behind closed doors" gear, in the bedroom, playroom, or dungeon.
My wife DIDN'T give me a choice.
She loved to squeeze a ball or both balls as hard as possible.
Then French kissing me and as long I responded that kissing passionately, she knew that she could continue.
Till the moment I couldn't bear it anymore.
This moment she used to ask me if I still love her.
My answer was always yes.