I suspect that most of the medieval torture devices were rarely, if ever used. Morbid curiosity and horror stories have always been a thing. Torture museums are a popular thing, and I can easily imagine people making torture devices just to sell tickets. The Iron Maiden is an example of a torture device that was just for show.

The value of human life was much less back then, so that it was a lot more violent makes sense. But I don't think it is specific to medieval Europe. People happily killed and tortured each other everywhere in the world. Modern western society is an exception, not the norm.