Meeting someone new while having a good time is generally considered a good way to find someone to date, but the tradition of being matched up by friends and family still lingers heavily in modern society. While there have been plenty of people recently who chose to use a dating website, there are still plenty of them who relied on the whimsy of fate to help their romance along. Almost any type of activity can do that, but not all of them are ones that will last as long as the relationship.
People today work hard, and they often find little time to relax when not striving for an important goal. For those who have found a steady relationship for dating or a partner for life, going out to have fun should still be part of the way they enjoy time together. It can be good for them, and it is twice the fun when being with someone they love.