I've always found this an interesting one, because whilst I'm in affiliate marketing, I'm also earning enough to make me comfortable, not rich.
Why? Because I don't like to word all that hard, and I like to do other things.
The really rich affiliate marketers are compulsive workaholics, or people that don't actually have the time to enjoy their insanely large houses, sports cars and Air Warfare Destroyer class Cruisers.
I actually think if you're actively attempting to earn more money than you need to be comfortable there's something wrong with you.
Money doesn't buy happiness. Material goods are not happiness. Whilst you think your problems are caused by a lack of money, the moment you're earning a six figure income, that argument is simply a logical fallacy.