Audio dares sometimes work better than visual ones because sound lets people use their imagination. When someone hears moaning or breathing sounds, their brain fills in the rest of the picture. This makes the experience feel more personal and different for each listener. The voice can also show emotion in ways that a picture cannot, creating a stronger reaction without needing to show anything.
Visual dares like flashing are over in a second and everyone sees the same thing. Audio lasts longer and changes as it goes, keeping attention the whole time. People can enjoy it privately with headphones, making it feel more secret and exciting. The human voice carries warmth and closeness that a photo simply does not have. But .... we still want to enjoy the visaul LOL, AND the audio. We want it all :)