Historically, most pagan people in the world would have agreed that marriage is for the alliance of a man and a woman, and for the procreation and raising of children. But societies differed greatly about whether or not love should be involved, or even consent. (Although usually the clans of the married couple were expected to consent, even if the couple disagreed…)
The more healthy a society was, the more it approached this sort of understanding. Monogamy is healthier than polygamy. Fidelity is healthier than adultery. Affection between spouses is healthier than opposition. Care for children is healthier than neglect or abandonment.
Also, many pagan societies had an intuition that there was something sacred about marriage, although they disagreed about what it was. (Usually they figured it was fertility, the alliance of families, or contractual obligation, although marital love was never out of the question.)
But the Catholic teachings about marriage are much more complete and explicit, and they draw lines about what is universally right and wrong about marriage. They also explain why even a natural marriage is something sacred, and how a sacramental marriage is something even more.