Actually it’s more of a non-traditional freak show. Along the lines of The East Village Comes To Brooklyn. Very post modern. But they do have some actual freaks…(I liked the guy who rolled cigerettes with his lips).
In some places, there are. In fact, this is the source of some of those funny-sounding laws, like “It’s illegal for a monster to perform in public in Cupertino, California.” People with various deformities were formerly referred to as “monsters”, and there are laws in various places against exhibiting or exploiting them.
I’d imagine that endurance shows were banned because of the massive popularity of them during the depression years.
There have been tv shows about this fairly short lived phenomenon, but one common type was endurance dancing - which usually ended up as a shuffling waltz with couples literally propping each other up.
I’d hazard a guess and reckon that desperate folk, public spectacle and money would produce a pretty tacky show and could result in injury or long term damage.
Endurance contests haven’t completely died out, of course, though the may require less exertion than in days gone by. For example, see Hands on a Hardbody