First off, just to be pedantic, you’re talking about weddings, not marriages.
Secondly, all those traditions you mentioned aren’t quite as widespread among heterosexual couples as you seem to think. Two of my friends were married in a field in Colorado surrounded by a circle of family and friends who each read a portion of the ceremony they had designed together. Colorado does not require an officiant.
My father and stepmother held their wedding ceremony in their dining room with a few family members present. It was a beautiful ceremony adapted from a traditional Korean peasant wedding (My stepmother is first-genration Korean-American) with vows written by my father. The (adult) children who were present participated, but no one officiated. The legal formalities took place seperately some weeks or months later when they signed the marriage licence in a government office with no witness or ceremony.
Different ethnic and religious groups may also have traditional ceremonies that are just as standardized as the ones you’re familiar with, but that differ from it significantly. Quaker, Catholic, traditional Chinese, Jewish, Hindu, Greek, and Mormon weddings are all very different from one another.