For me, it's more about the competition but money does have some consideration. Some of my favorite tournaments don't even have money involved. There is a charity tournament held in my area once a year that is fun and competitive with the money going to different charities. They have a huge raffle and give trophies to the top 5 places.
The APA holds the US Amateur which is a lot of fun to play but involves no money. Just pride and competition. Everyone plays with different motivations whether it's to challenge themselves with competition, the camaraderie, the money, or the recognition. Such with many things in life, It isn't black or white. I suspect most play for a combination of different reasons.