A good question to ask about why organizations exist is to ask, “Who benefits?” Political parties exist to help their members to influence what laws are made and how they are enforced–in other words, to get into power and benefit the interests of their own social class.
For example, farmers usually have influence greater than their numbers would suggest by voting as a bloc on their issues, such as farm subsidies. Farmers are paid for not growing certain crops, because that keeps the price of food up and gets them more income–a wierd form of group socialism that harms the poor who are trying to eat and feed their children but benefits farmers.
Actors and dancers and artists believe that the arts should be subsidized for the good of the country’s culture and reputation. It’s incidental that subsidizing the arts would give more of them a living doing what they like to do.
Being a priest is a wonderful way to get an income without actually having to produce anything. However sincere, he gets paid to utter magic words and make mystical signs and ask for miracles, just like the witch doctor of a village. And with as much reality behind him.