Older guys like me tend to wax nostalgic about plump little hobbits with hairy toes who adventure despite their fear of it; and we like our gear to be historically accurate straight from the pages of Prince Valiant. Forget modern fashion; we like our characters medieval. But like it or not, we're all products of our time and see ourselves through the prism of whatever generation we happened to grow up in, with a fashion sense to match...
Gaming, with its rulebooks and miniatures, is a surprisingly visual medium, especially for theater of the mind stuff. That said, it's always depicted personal grooming by the standards of the day because that's how we see ourselves and, more importantly, how the customer sees their most idealized self. Paradoxically, depictions of armor and equipment have moved steadily away from historical accuracy towards the increasingly fantastical because these things have no contemporary parallel. Let's call it fantasy fashion.
We form our standards of beauty and style growing up, although I won't pretend the 70s or 80s had a clue about some things. And as D&D and its imitators became products marketed to others, it only made sense that buyers see themselves. Hence, the piercings and body tattoos that started popping up in the 90s in time with contemporary fashion. But armor and equipment changes in response to stylistic shifts, which are far more subjective.
Anyway, we can see this trend play out across the decades of the hobby:
1970s: The Tolkien Calendars offered a gorgeous look at Middle Earth, courtesy of the Brothers Hildebrandt. Nice, but their depictions were definitely a child of the times. Aragorn had a serious pornstache and everything had a 70s vibe. Fantasy wasn't mainstream yet, meaning no need for mass marketing. The clothing mostly followed a historical template or cinematic precedent with Robin Hood tights and storybook tassels. D&D did the same, owing to its identity as a pseudo-medieval wargame, with an emphasis on accurate armor and weaponry. I have a soft spot for this, especially the 19th century storybook look.
1980s: Fantasy had gone mainstream, and it all converged on D&D. Larry Elmore was a dominant force here, and the 80s slant was undeniable. I've always felt like his artwork channelled He-Man just a little too much; but that's obviously a personal bias and in no way reflective of his great talent. Let's be clear: I couldn't draw my way out of a bucket, so no poisoned pens, please. But Elmore was also a child of his time, and demographic changes were increasingly on display; especially in the women's hair, which looked suitably blow dried. Snarfquest absolutely nailed the 80s in terms of personal grooming.
1990s: This decade saw big changes. The mainstreaming of fantasy, begun in the 80s, propelled its fashion far from any historical blueprint. Starting with 2nd edition's apocalyptic Dark Sun through D&D's third re-imagining, the humans sported body tattoos and various piercings as the non-humans became exotically alien, especially the (almost insectoid) elves and (muscular) halflings. Armor and weapons also got the extreme treatment, with heroic, sometimes ridiculous, proportions to match characters who were increasingly superheroes in an Iron Age Star Trek setting. Looks-wise, it was the MTV generation slaying orcs.
2000s: The rise of self-publishing changed everything. The hobby was less of a monolith, and independent voices had more of a say. The art, and its implied fashion, was quite literally all over the place. Of course, the rise of the OSR saw a return to the hobby's more traditional leanings. Peasants looked like peasants, and the halflings were fat with hairy toes after a decade of channeling Adam Ant. But this conservative pivot stood alongside some great modern fare, proving it's not a zero-sum game; and while I prefer the pseudo-historical approach, there's no wrong way to do this. It's called fantasy for a reason.
Art imitates life; and if we somehow get to 10th edition D&D, we can be damned sure its characters will look suspiciously like what the kids are wearing. This isn't new. Conan the Barbarian looked like a silent movie hunk on the covers of Weird Tales. But fantasy is a convention-busting genre. There's always some new creative vision; and just like art deco once ruled the popular fashion, kids will find new ways to see everything from warrior kings to the weapons they carry into battle. After all, what always changes can never die...