Tinder and other online dating options are pretty bleak and inherently extractive in nature, so I find it equally plausible that many young people are simply turned off from the whole thing.
They also weren’t seen as the primary purpose of sex.
Today, if you say something like “Sex is important and should only be done between people that are getting married, since it correlates with lower divorce rates”, most people will think you’re strange.
The birth control pill also enabled many of these attitudes, so it almost by definition wasn’t a return to their “true nature.”
But yes of course people like having sex. What’s new is that this pleasure-focused view of it has become the dominant one, to the exclusion of all others.
Traditional cultures would do a lot to control the sex of their unmarried daughters, because that would mean babies to care for and that means a lot of additional troubles.