Indoctrinated by the relentless, repressive optimism of the Protestant work ethic, Americans don't understand that in order to truly appreciate happiness, you must fully know sadness; and in order to be truly sexy or beautiful, you must have a certain capacity for ugliness that brings your handsome features and charming qualities into sharp relief. This is why conventionally attractive people are widely palatable (i.e. "conventional"), but very seldom sexy or beautiful. Just think of Taylor Swift or Kendall Jenner, both youthful, pretty, leggy, and woefully unmemorable. Or, consider the mystifying success of Brad Pitt, who is a mediocre actor in addition to being a sorry male specimen, whereas his so-called doppelganger, Benicio del Toro, is not only a stellar actor but also incredibly attractive, in a louche, rakish way.
Sex appeal and beauty are two vastly different, sometimes mutually exclusive things, but both depend on idiosyncrasy and imperfection. The best faces are those which, in the wrong light, threaten to slip from the sensuous to the grotesque. (Every great sculptor from Michelangelo to Bernini knew this fact, and exploited it.) The American standard of spray tan, washboard abs, and a smile so white it's blue is stupid because, often, the sexiest thing about somebody is their bad teeth.
It pathologizes the very factors that have always informed sexual attraction, like whether someone is subconsciously familiar to you or whether you find their scent compatible (only in America is personal smell rebranded and, then, monetized as "body odor," something unpleasant, unwanted, that requires eliminating). In scrubbing atavism in favor of metrics, it loses sight of instinct. So people forget to question whether a Brad Pitt or a Taylor Swift is actually hot, or if that's just another free-floating received idea. Today, when good looks can be bought a la carte, they forget that "hotness" is not just a matter of being thin or stylish or a boss with Groupon, but usually comes down to something ineffable.
Of course, such a narrow, unilinear view of attractiveness is perfectly in line with the American way, which represses inconvenient truths and socially unacceptable emotions as inherently "negative," and views negativity itself as ultimately unproductive. Incidentally, this is also the problem with Silicon Valley solutionism, which aspires to engineer a whole host of maladies—from inconvenience to depression to mortality itself, out of the human condition—without grasping that to not experience those things is to cease to be human.