The traditional concept of marriage has changed over the centuries and is becoming less central to people's lives as evidenced by the rates of adultery, divorce, open sexual relationships, social security for single parents, the intentional procreation of zygotes in fertility clinics and the number of children being born out wedlock.
I believe traditional marriage has become irrelevant in today's society. More and more couples are choosing to remain together without marriage. This may have been unheard of in our Grandparents time, but it is perfectly acceptable now, and has also become the norm. Not so long ago, couples lived together without being married until children came, then decided to tie the knot. This is no longer the case. I think celebrities may have played a large role in this, putting it out in the open via the media.
With the divorce rate as high as it has become and with more acceptance of various types of relationships, we are seeing where marriage is becoming increasingly unnecessary in its legal sense. Both people should be independent financially and that makes it unnecessary to marry unless there are children to provide for.
No, traditional marriage is not irrelevant to current cultural norms and societal standards. While there is diversity in modern relationships, people still regularly choose to form bipolar couples on a regular basis. What is changing is the makeup of these relationships, such as allowing two men or two women to marry. People value the formality and institution of traditional marriage as a right and a privilege, making it unlikely that this form of legal and religious ceremony will ever go out of style.
Maraiage, and I am including gay marriage, which is essentially marriage. Marriage is relevant since is creates a formal and formally recognized union with responsibilities, benefits etc. Marriage is relevant in society as the basis of a family unit regardless of the size, shape, color or gender of the family.
Traditional marriage is not irrelevant in today's society, it stil stands and is used more than any other type of marriage. People like to get married and to have one partner to share the rest of their life with and to enjoy having a home in with. It is still very relevant.