I don't know if discussing "practical" Armor really makes sense in the context of videogames since what you need it for is pretty impractical in the first place.
The various class and income implication of armor aside, it tended to also be heavily specialized.
Like, wearing full plate is something you almost exclusively did on horseback. Formation, intended movement speed and weapon systems also heavily influenced armor choice as well as what weapon type you are facing. There were plenty of breastplates that only cover the front, since in formation, you didn't need to protect your back as much.
Spears are super underrepresented in games - and a lot of older armor is primarily designed agains spears (and missiles) since those were the most common weapons you used to face. How useful would full plate be against a dragon or other huge monsters? It wouldn't be. Since that is not what plate armor actually protects against.
even games that at least try to be a bit period accurate, like a witcher, have mostly "rule of cool" designs rather than anything pracitcal.
My point is mostly that the problem with needless sexualisation of armor in games is that it's needlessly sexualised. The armor the dudes wear is often just as silly - just in different ways, especially when it fully covers the body.
Most armor, or at least the historically "remembered" armors, tended to be more vanity than practicality (a big part of armor was about status and wealth). Even though plate armor was extremely effective at protecting against blows, it greatly limited movement and was generally only worn by aristocracy (who only rarely actively participated in battles). The few knights who actually did wear it into combat were greatly protected but also weren't nearly as effective as all the archers and pikemen. Regardless, anyone sane would never wear close-fitting armor (or close-fitting clothes under armor), as that completely defeats the intended purpose. Armor, whether modern or medieval, is attempting to cushion the body from blows. Form fitting is anathema to that goal.
More than any other artifact of war, armor dominates visual images of medieval Europe. From the chainmail carefully stitched onto each warrior in the
www.warhistoryonline.com
As you say, armor as depicted in fiction has little to do with practicality, and is much more about following rule of cool. Or in the case of every fantasy gacha game, rule of bikini armor. That said, it is particularly galling to see armors with tit windows that otherwise look like functional armor (it's like putting a STAB ME HERE sign on your clothes). It's just... kind of an extra layer of stupid.
Like, aside from the gross sexualization, the fact that neither the human body nor metal bends that way drives me up a wall (
seriously, making armor this way would be ridiculously complicated and extremely fragile). The armor has to be like... floating in front of her, because it could not physically be worn the way it seems intended. And what's worse, is that nearly ALL the males are wearing armor that would be at least somewhat practical in a medieval setting.
Ugh. Just fucking frustrating any way you slice it. Shitty design, zero imagination, no care for artistry or function or consistency. Always the same with the game industry, "hurr durr girls boobs! me like boobs!" Thanks. We're glad your inner horny fourteen year-old can dissolve any chance of people ever taking the medium seriously.
