Freak shows were characteristic of carnivals. I don't know if they still exist, but if they don't in the form they have in the past it seems we can't do without them as we've managed to replace them with something similar. They must satisfy some need we have. It delights us in some strange sense to see people who are deformed even if they're repulsive. My guess is it does so because it makes us feel we're better or at least normal when compared with those who clearly are not, provided they're displayed in a manner which poses no threat. They provide us with a kind of reassurance. Through them we think ourselves acceptable, and demonstrably so.
There are those of us who still enjoy the deformity and disability of others, I'm sure, but we're not as willing to express our enjoyment as openly as we did and could when invited to view freaks of nature as they were called by paying a fee and visiting them as they posed in tableau at some local fair. Much as we are inclined to inflict pain on others, there's been a decline in the tendency to do that publicly, although our recent toleration and approval of hate and the hateful on the national stage makes one wonder whether that decline will continue. One doesn't want to be accused of "political correctness" after all.
I think freak shows have been replaced, by reality shows. I suspect others think so as well. The similarity is fairly clear.
Some reality shows unashamedly center on people who are physically uncommon, e.g. they are morbidly obese. Some center on people who have problems of a particularly disturbing nature, which impact others visually, e.g., hoarders. Their lives are displayed in detail. Generally, such shows also are carefully structured to have, in most cases, a "happy ending" where there is some kind of redemption or at least the hope of redemption. The physically unusual is somehow rectified, a house full of rubbish is cleaned. Nonetheless, peculiarities, physical or psychological, are on display for our entertainment though we watch them from some comfortable, private venue and not at a public showing.
Some modern day "freak shows" are more subtle, however--if that word can be used when exhibitionists are observed by voyeurs. They involve anything from people beating one another senseless with fists and feet, to people brought together in an unusual environment and manipulated in certain respects so that the manner in which they react is displayed, to men or women being romantically paired with a number of women or men and made to choose one or another of them for marriage while we watch. In the case of such shows, what is put on view for the public at large are not physical deformities or psychological or mental deficiencies in particular. Instead, individuals are treated as freaks once were; they are made the objects of our attention, our review. We watch them and marvel at them or use them by comparing them, usually unfavorably, with ourselves. They become freaks, eventually, if that suits the producers or directors of the shows.
Freaks shows and reality shows appeal to the voyeur in us. A voyeur is not necessary someone who derives sexual pleasure from watching others, but may also be someone who enjoys the pain or distress of others and wishes to observe it, or to observe people in sordid or scandalous circumstances. They appeal, in other words, to what is base in us and we debase ourselves by watching them. Their appeal and popularity doesn't speak well for us or our hopes for improvement.