A phrase you sometimes hear, especially in the context of the 1950s and '60s, is "Every generation thinks it invented sex."

Over-literate high-tech corollary: "Every generation thinks it will destroy sex."

That said, there is legitimate bad news. I don't doubt the numbers ascribed to Japan (25% of men and 45% of women having no interest in sex). In the U.S., among people over 25, you'd probably see similar numbers. And this is in spite of (or because of?) an over-the-top sexualized pop culture that is obsessed with adolescence.

In fact, extended adolescence is the problem. Humans have two sex drives. One is r-selective and peaks around 17. The other is K-selective and peaks around 35. Stereotypically, men have a stronger r-drive than women and women have a stronger K-drive. In practice, probably almost all humans have both, and age/gender differentiations are properties of the aggregate. (Differences within groups are greater than those between groups. There are K-heavy young men and r-heavy older women.) The r-selective drive wants variety, escape, and often not a small measure of depravity. It's socially unacceptable and people don't really admit to it, and most would rather ignore it. The K-drive is the wholesome one tied to long-lasting emotional bonds and that built civilization.

Negative stresses provoke the r-drive and squash the K-drive. This makes evolutionary sense, because the r-drive's purpose is to repopulate after a catastrophe, and the K-drive (quality over quantity) flourishes in stability. That's why extreme income inequality is actually dysgenic, despite the love for it by "Social Darwinists". It encourages reckless, r-driven sexuality in rich (to assert power) and poor (to escape). It diminishes the K-drive because people look to the future and don't really want to bring children into it. The result is that you have more people born of r-driven couplings than K-driven, and the r-drive doesn't much care if the other person's intelligent... The good news (and if you don't think this is good news, you're not literate) is that, thanks to birth control, the r-driven couplings rarely produce new people. No one likes when girls go for bad boys (or when men go for useless ditzes) but thank fucking Xenu that those couplings aren't producing new people at anywhere near the historical rate.

Japan actually has a low level of income inequality, compared to the U.S., but it has a hierarchical work culture. Being someone's subordinate for 8-12 hours per day just murders the K-drive. The stress of subordination stokes the r-drive which would, in 700 AD, be inclined to rape and pillage, and with probably less of the pillaging. However, modern society gives a plethora of healthier, legal and less dangerous outlets for that r-drive: pornography, video games, Internet trolling, prostitution, bizarre and often violent cartoon media, or a casual-sex "pickup artist" "Game" that, while still unhealthy and disturbing, is far better than the pre-modern practice of starting a war as an excuse for society to (a) kill off some surplus, low-status men, (b) acquire resources for the low-status men who survive, and (c) give those angry, low-status, otherwise sexless men a chance to rape people. These surrogate activities are much better than their ancient, barbaric predecessors.

In broad strokes, the picture we see is that the pervasive subordination (involuntary extended adolescence) inflicted by corporate dominion squashes the healthy, K-selective, sex drive and that, while it encourages the r-drive, that's one that is best met through means other than sex.

Is this going to kill sex? Nah. Society is sick, and the supposed "sexlessness" trend is one of the ways people are dealing with it. Technology is providing healthy replacements (and sublimations, like video games) for the r-driven sexuality that wasn't much good for human civilization in the first place. K-driven sexuality has been reduced (temporarily) by society's over-reliance on hierarchical work structures that (a) make the vast majority of people subordinates, (b) resulting in an epidemic of involuntary extended adolescence, and (c) make forward-thinking people disinclined to bring children into a broken, burning world. The picture looks bleak, and society is really sick right now, but is society going to die? I doubt it (unless an environmental catastrophe intervenes). I think the culture is at or near a nadir. It might be worse (perhaps a lot worse, perhaps violently worse) in 5 to 10 years, but in 30 years, human civilization will be better than what it is now. And so is sex going to die out? Not a chance.