Marriage is under attack in the UK. It has been humanity’s default mode of handling sexuality since the dawn of time. Whether or not it was accompanied by public ceremonies or religious rites, heterosexual marriage has been normative. Polygamy, by far the commonest alternative arrangement, has been the habit of only a few.
Such bonding is quite remarkable. Imagine what life would be like without it. If we treated sexual partners like holiday vacations, rarely returning to the same place twice, men would never know how many children they have or who they are. Women would be given the entire responsibility of bringing them up and providing for them. A moment’s thought shows how logical and inevitable heterosexual marriage is.
So the family unit has always been the basic building block of society. Alternative community arrangements have occurred, but few are enduring and have rarely found wide appeal.