My sister used to moan about how marriage was just a certificate imposed upon us by a state ruled by the machinations of a defunct religion, and in fact if you love someone you will stay with them and have children with them and that is the marriage; the staying together. I actually agree with most of that though as you dig into the thoughts there are others one has to clarify such as, is having one partner natural and isn’t it possible to love more than one person in a lifetime? Obviously it is otherwise we wouldn’t have divorce.
But I am actually of the opinion that you have to have a certain mind-set for a marriage to work. It is not a mind set than all men and women have and in fact the world is a better place for the fact that about half the human race are not suited to marriage at all (if divorce statistics mean anything.)
The problem is the very state that requires marriage to enhance tax regimes, and settle habits in its population because that state tries to force people to think in the same ways, and that is always a mistake. It’s a bit like a millionaire telling you anyone can make money, palpably untrue. Just because one marriage works, or a million work, doesn’t mean all will work or particular ones are worth striving to save.