There's also the big benefit of essentially eliminating STDs.
In my view, a lot of it comes down to what does sex mean? To me, sex says "I love you so much I want our love to overflow into new life. I love you so much I want to raise a child with you." Raising a child within a marriage is generally much better than raising a child outside of a marriage.
> restriction on contraception
One big problem with contraception is that it's not reliable. The pill has a 7% failure rate on average, and condoms have a 12% failure rate on average. People use contraception thinking it will prevent a pregnancy, but they're wrong.
> benefit of a socially powerful elite
I don't really understand how a prohibition on fornication benefits a powerful elite. The elites in the media industry seem to be promoting fornication in movies, TV shows, books, videogames, etc. I think elite men often want to use their position to have sex with a lot of women, which would be easier if women are ok with fornication. Also they won't be regarded as hypocrites if they say what they're doing is ok. Take for example Aziz Ansari. A woman accused him of some bad sexual thing. Much of the media defended Aziz saying it was just awkward sex, and that's not unethical. If Aziz had been publicly against fornication though, the media wouldn't have defended him.