Relationships, sexual or otherwise, are not subject to paperwork. The days of relationships, sex, or even reproduction being tied to marriage are long gone.
It’s stupid because the combination of singles mixers, tinder, and community events make it very easy to find a partner (keeping them is another story) but nobody wants to try. I’m of the opinion that porn has sapped their will to find women, even though it’s very possible to have a healthy relationship with porn and men have indeed had healthy relationships with porn throughout recorded history.
Having all of your sex come from porn is like having all of your meals come from McDonald's. And that's a choice you can make. It's probably not the best choice, but a fair number of people do in fact make it.
You can construct your family in a lot of different ways. Having a lot of friends, some very close friends, and zero lovers is a perfectly valid one.
At least, it was becoming such. Legally, there is more and more push back against structures other than one male and one female, who are each other's sole and perpetual means of support.
Some people have decided that they don't need a relationship to be happy. They've found other ways to cope. For some this may be sour grapes. But that's another coping mechanism in itself!
Because stringing along some poor soul that looks for actual relationship and let her waste months to figure out this relationship was never going to happen sux.