nonsense
Why do you think people get married and stay together for 50 years?
You say love is something on the level of a primary school child, but it takes more than that to keep families together.
Children need their parents. Since all babies come from sexual reproduction between one man and one woman, we have marriage so those children will have their parents.
A pregnant woman needs someone to provide for her, so she makes the man agree that he won't be off getting other women pregnant and providing for them instead. A man doesn't want to work every day to provide for someone else's children instead of his own, so he makes the woman agree that she won't be getting pregnant by other men.
If you know where babies come from, you can see how marriage is all about children. Even if a woman can't get pregnant, she still needs her husband to provide for her instead of sleeping around and spending his money on other women.
Because the government started paying women to raise children away from fathers - providing for women's needs with men's tax money - we have millions of boys who grew up with no male role model. So they act like their moms, believing that life is all about attracting a different man every week for attention and self-esteem.