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I cannot agree. I saw no adequate establishment that marriage has to mean one person sacrifice for another. What if the couple have common interest, common goal and they can afford one or several full time maids to deal with the trivial parts of daily life? 1+1>2, such examples are too many. And what do you mean by entropy here? How have you formed your theory system (not just grabbing a term from chemistry and/or information theory)? Family does bring people happiness if people meet right people for them.
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It is true that not all marriages involve sacrifice but the scenario indicated by you is extremely rare. Statistically speaking, this can be ignored as outlier. Please think about these questions: how many families in the US have the luxury to afford full time maids? Do you think a family income at $120,000 per year would be enough to afford a full time maid to deal with their daily living? Just a reminder: only about 2% US population have above that income. In addition, the “right people” in your comments happens only in a fairy land.

In modern society, everybody has his/her interest. However, the current mainstream performance of marriage is not solely based on interest, but more likely based on romantic love. Romance will likely wane surprisingly quickly. Furthermore, marriage involves not only pursuing personal goals for the couple, but also raising children. If you think adding children will add happiness to the family, you are wrong. As a matter of fact, about 70% (?) American families believe that raising children is a burden, rather than a pleasure. The divorce rate peaks just a couple years after the marriage, or in other words, at the time when their children are still young.

In traditional marriages, women are unfortunately trapped in their marriages. Taking care of husband, raising children, and mentally supporting their husbands are main tasks. However, after a couple years they are left with deeply wounded hearts. Even without divorce, the depression rate is higher among married women than men. Is this a coincidence, I don’t think so. Do wives sacrifice their goals? Sure. They can finish their college education, find decent jobs, and thus support themselves. In Sweden where the government takes a large part of family responsibilities (e.g., government sponsored child care, a long paid maternal leave, free health care from beginning till the end of life), half of kids are born out of wedlock. It is simply due to the fact that there is no need of family to raise a child.

Your example of family in which the couple has common interests and in which kids are raised by others (by either maids or government) indeed reflects my point of view: future family will be based only on common interest including love. If the interest does not exist any more, family will be easily dissolved. The concept of marriage is probably not in the traditional sense. However, till now this is still a utopian view.

In addition, it is of interest itself to point out that in social science, we always deal with general population, which allows outliers. One counter-example won’t invalid a social theory. It may provoke more thoughts though.
In terms of entropy or whatsoever, it just happened that my brain randomly associated that word with my marriage theory. It is a little flavor to attract readers’ eyes. Did it work?