Since 2008, the production of pornographic films has been banned. The State Administration of Radio, Film and Television's prohibition on pornography has been complete.Any film studio found in violation may have its license revoked. Possession of pornography is punishable by up to 3 years in prison, a fine of CN¥ 20,000,

The emphasis on prudish relationship norms dates back to the Maoist period, during which cultural icons were portrayed as living without sex and marriage.

Using artificial intelligence, Chinese Internet censors today are superb at detecting sexual images. Tech companies such as Alibaba and Tuputech developed algorithms to trawl various online platforms, for pornographic audio, photos, and videos with remarkable accuracy. The search engine Baidu reported removing more than 53 billion pieces of “harmful information” using artificial intelligence in 2019, almost half of which were pornographic. The public security bureau squelched more than 43,000 pornographic websites last year alone.

The most intense censorship campaign, called “sweep porn and attack rumors,” came under President Xi Jinping’s government in 2014. The new attack not only promised to arrest website operators, it also banned the use of television satellite equipment that allowed access to foreign broadcasts, confiscated hundreds of thousands of illegal publications in print, and prosecuted what officials called “fake journalists” along the way.

Interesting thing is that during industrialization different states behave very similar way.

And it is simple economics thing, as in the minds of government you don't want resources (time) spent on it or it will hurt the economy.

As most of effective new workforce in this period is in 17-30 years you need strong Church (as was in case of early industrial countries or Muslim states now) or central government crackdown on anything increasing time spent on sex.

Very high home prices and dormitories design also help here. Intent is to have people working like most efficient screws in machine not spending time and energy on anything but working, eating and shopping.