Above is an image from the 1963 film Jason and the Argonauts. I don't know if I saw the film when it was first released, but was a preteen, at least, when I first saw it, at a drive-in theater, I think. I was quite impressed by the fighting skeletons, and the appearance of the gods in various parts of the movie. Poseidon was there, as I recall, standing in a pool of water pushing what I assume were fiberglass cliffs apart to allow Jason's boat passage. There must have been others. I think there was a hydra. I can't remember if the Furies were involved or not. They were in some movie I saw back then, in any case. I enjoyed these garish displays.
Curiously, fighting skeletons figure in our fantasies once again. Entire armies of them in various states of decay appear now and then in Game of Thrones. There must be something about them we find attractive.
I can understand how a preteen and even a teen might enjoy fantasy films along the lines of Jason and the Argonauts. I find it more difficult to understand why an adult would, but it would appear they did, and do. They would have to, in order for such films to make money. Of course, adults may have been and may still be required to attend fantasy movies with children, like those churned out relentlessly by Disney, but it isn't clear to me that they would enjoy doing so. I saw quite a few of those myself when my daughters were young.
I may be wrong, but it strikes me that young and old now are consumed by fantasy, far more than they have been in the past. Games and all forms of media are devoted to it. I have no figures on which to base a comparison, but my guess is that there are far more fantasy stories, games, films, TV, books than there are history, or biography, or documentary non-fiction or historical fiction, and even science fiction. Perfectly respectable and able writers of science fiction such as George R.R. Martin and C.J. Cherryh have lept into fantasy as a genre, creating wizards, mages, dragons, knights, quests of all sorts to entrance us. It's like the second coming of Sir Thomas Malory. This isn't even to mention the vast mound of fantasy erected by J.K Rowling and others, or comic book fantasy like that involving X Men, or Captain America, or Superman, Batman and assorted other super or supra men and women which permeate popular entertainment.
Has this always been the case? I doubt it. I suspect it's more a phenomenon that arose in the 20th century, when the written word and film became more readily available to us all. Technology makes media omnipresent and even more available now. Magazines, comic books, novels, TV and movies were all available in the 20th century, but now are almost obsolete as computers, laptops, tablets and smartphones provide access to everything to everyone.
Fantasy and magic were common in the ancient world but were common because what was thought to be real included them as part of our lives. Gods were everywhere, as were stories involving them, and divination and magic, sometimes by or of the gods and sometimes of demons or those men and women who knew how to invoke their power. Even those philosophers who doubted the common myths involving the gods took them seriously, recognizing that they were real and powerful to most others. They had a profound practical impact on daily life.
That's not the case now, however. Now our reality, our lives, are godless, without magic, without heroes. We can't believe in them, or are in any case wary of appearing to believe in them as part of our day-to-day lives. But we want them to be or at least wish they were. We may even hope or possibly believe they can be, if only....something. The world, as we know it to be, is not enough.
So our dreams and imaginations are populated with them. They're everywhere but "here." And they mean more than anything else because we can't accept their absence. But though there may have been a time when the supernatural or fantasy figures which were made part of religion after the fall of paganism, and which incorporated much of the pagan, sufficed to allow us to tolerate the real, that time seems to be gone. We're more likely to believe fantasy than religion, however fanciful that religion may be.