People who graduate from college earn more money than people who don't. This is a statistical fact.
Unfortunately, a lot of people seem to be under the impression that, therefore, any given human being, if permitted to attend college, will necessarily earn more money once they get out. I don't believe the causation runs in that direction.
You have to have good grades from high school to get into college. If you have good grades, it's likely either because you're naturally smart or because you work hard - and either one of those things will allow you to excel in your chosen field.
You have to have opportunities from friends, family, and government institutions to get into college. If you have opportunities from friends, family, and institutions, you can also likely use these things to excel in your chosen field.
Certain high-paying professions - doctors and lawyers and such - require higher education. That's certainly skewing the graph.
You have to have - if not money, at least financial opportunity in order to pay tuition. Coming from money is certainly correlated with getting money (and, if nothing else, student debt will incentivize you to earn more money, even if you don't get to keep any of it).
If you get arrested in your late teens or early twenties (the age that most people are first arrested), you likely weren't able to finish college. People with criminal records make less money.
I could go on. My point is that higher education is certainly correlated with financial success, but absolutely does not guarantee it. I would say one of my life's greatest regrets is attending college for three years, under the misapprehension that the high-paying nine-to-five I deserved would be waiting for me on the other side.
That's one of my greatest regrets and I didn't even have any student debt.
I guess this is all sounding like I'm anti-college, and I'm certainly not. I love learning! By all means, if you have the opportunity to attend an institution of higher learning, take advantage of it! But do it because you want to learn and grow. Learning and growth are what schools are for, regardless of how they may advertise themselves.