Fetishes come from the taboo aspect of something.
So there shouldn't have been an ankle fetish lately, to keep your own example, since showing your ankle isn't taboo since something like 90 years now.
Aren't you confusing taboo with the transgression of a prohibition ? Taboo are purely moral, and not related to the effective prohibition of something. In more or less half of the world, incest is something legal as long as it's between consenting adults. Still, it's seen as a taboo in most of the world, including countries where it's legal. At the opposite, there's many countries where nudity is absolutely not a taboo, but still something totally illegal in public places.
Anyway, whatever it's the taboo or the legal transgression, like I said corset fetish is a thing, like stocking fetish, leotard fetish, feet fetish, and so many fetishes related to something that is neither a taboo, nor prohibited. In fact all the fetishes corresponding to the strict definition of the word are neither a taboo, nor prohibited, since they are initially a derivative to the effective sexual act. Its only on the extended definition of the word, that include things like anal fetish, BDSM, and so on, that you can found fetishes targeting a taboo (deviancy) or fetishes targeting a prohibition (transgression). But even in this case, it's not mandatory. Fetishes are practices that trigger and/or increase the desire, and you don't necessarily have to add the spice of deviancy or transgression to achieve this.
Since I named BDSM, I can see the potential taboo, as well as the potential illegal part, in the role of dominant, but I fail to see both in the one of submissive. So what ? Being dominant is a fetish and being submissive not ? Same for bondage, where being the one with the rope can potentially be seen as a deviancy or a transgression. But I don't know a place where it's taboo or illegal to be tied. So here again, it is, or not, a fetish, depending of the place you occupy ?
What I was saying is that the prevalence of any specific fetish is tied to the society at large. The corset thing, for example: sure, women stopped wearing corsets eons ago, but nostalgia for the "good ole'" victorian times is alive and well.
Except that people who have this nostalgia are generally also against those sexual deviance that are fetishes. And I don't even talk about all the parts of the world where "Victorian times" mean nothing more that a boring hour in history classes, when it don't just mean absolutely nothing.
Homosexuality is no longer a fetish, it has graduated into a way of life and is somewhat accepted, at least in most civilized societies.
What ? Homosexuality is a sexual preference, it never was a fetish, and isn't at all a way of life.
P.S. : Also, voyeurism will never disappear as long as the culture promotes the nude human body or the act of sex as something shameful or something not to be seen in public.
Do you even know what voyeurism is ? When a voyeur look under the skirt of a girl, he don't expect to see her sex (it's the cherry on the cake, not his goal), nor a micro man having sex with her, or just geisha balls.
Anyway, there's many countries where nudity and sexual acts are seen as totally natural. They are still prohibited in public place, but not because it's something shameful, just to protect children from something that can potentially be traumatic for them. Yet, being prohibited in public place doesn't mean that it's prohibited in public. There's many countries where you found, not just nudist beaches, but nudist campsites. Places that are small towns where you do everything, including buying your groceries by example, fully naked. And nobody care at all outside of them. There's also many countries where parents don't care to be naked in from of their children. And among all those countries, many are Western ones.
And in all those countries, voyeurism is still an effective fetish, even for people who also frequent those places, or are used to nudity since their youth. Voyeurism is the pleasure to see something that you shouldn't have. For some, it explicitly need to be related to sexual part of the body. But for some, seeing a shoulder under a shirt is enough to increase their lust. Not because it's, by itself, sexual for them, just because the said shoulder should have stay hidden under the shirt of this unknown girl. And, once again, there's nothing taboo, nor illegal, in the fact to see this shoulder...
