I didn’t think they really had a point, other than just tradition, but I went to wikipedia anyway to satisfy my curiosity. There is some pretty interesting info on the origins of bridesmaids, like this:
“The Western bridesmaid tradition is thought to have originated from Roman law, which required ten witnesses at a wedding in order to outsmart evil spirits (believed to attend marriage ceremonies) by dressing in identical clothing to the bride and groom, so that the evil spirits would not know who was getting married. Even as late as 19th century England, there was a belief that ill-wishers could administer curses and taint the wedding. In Victorian wedding photographs, for example, the bride and groom are frequently dressed in the same fashion as other members of the bridal party.”
It’s like their only purpose is to serve as a meat shield for the bride and groom against curses and ill wishes. Remind me never to accept a position as a groomsmen.