To be honest marriage is and it will always be relevant for society, but I don't think people in a relationship have to get married because when you really love someone, you will love him/she in all of his/she forms, to be honest marriage really doesn't change that point of view. People should not get marriage because of tax benefits or another motive whatsoever that Is not love for your partner. You could easily be a committed couple to stay together for a really long time without getting marriage, is more like: when there is love, it is second to none.