>>43396
> is the main reason of marriage is to ensure that a man will stay with a woman and help her to raise children since human kids are much harder to raise compared to other infant animals?
That could be one of the reasons, but restricting intimacy to marriage is not for sure going to turn all those guys with 'hit it and quit it' behaviour into loyal husbands. Marriage in Islam keeps women from ending up in that predicament, puts barriers of entry, only someone who cares for the woman and is sincere is going to go through the trouble to marry her.
Mainly the reason for marriage is because we're not animals, we are civilized who make civilizations, and the family unit is the basic building block for such societies. A family is best for all parties, even if we just talk sexually, within the structures of marriage you will have more sex, thats why if you look at stats today in the west they say younger generations are having less sex today, because less are getting married especially at young ages compared to the past, people have to put in much more work to get sex if they're single. Theres ultimately many reasons we can point to for why else marriage is beneficial.