The benefits of a college education are many. They include learning about the world around you, personal skill development, developing important contacts, and a clear financial advantage.
The first big benefit of higher education is learning about the world around you. The vast majority of high school students have a very narrow world view. They probably haven't needed to learn to work closely with people from different cultures and countries. Overcoming a cultural difference when it comes to accomplishing goals or collaborating on projects is a fundamental ability for anyone who plans to be a part of a team career-wise. Young people high school age or younger tend to spend all of their time with people who have similar backgrounds and interests as they. Being exposed to a broader spectrum of attitudes and ideologies develops the ability to see situations from different perspectives – the much-touted "thinking outside the box" all employers look for.
There is no part of university curriculum that can't be learned free at a good library. Because of this, the book-learning is actually secondary in terms of what skills a student develops. The more important skills that a student develops are reasoning, communication, and collaboration. The irony of our school system is that all the way through high school, students are constantly told "keep your eyes on your own paper", "don't ask your neighbor for the answer", and "no talking during the test". While there's a certain amount of necessity in this approach, it's often a culture shock when a young person enters the work force and hears "If you don't know the answer, ask somebody who does", or "don't waste time reinventing the wheel, if somebody has already done part of the work, build on that ". Higher education gives a young person to make the mental transition between the two outlooks. In the workplace, acting like an honest student will get you labeled an uncooperative employee.
A huge benefit of higher education is the network of contacts that a student develops. I'm not talking about the stereotypical New York stockbrokers making trillion deals on the 13th green. What I'm talking about is that situation everybody finds themselves in at some point in their career, when they are thinking of making some change or taking a risk. During this time, a person needs someone to bounce ideas off of. That someone needs to be able to comprehend the details of the situation – in other words: someone in the industry. The problem is, most people are too busy doing their jobs, they don't make it a priority to meet other people who do the same job. Anyone they know in the same company or city could be someone they wouldn't feel comfortable discussing the situation with. This is a function of lack of trust. It is wonderful to have people you do trust who understand your business.
According to the US Census Bureau, someone with a Bachelors Degree makes roughly one and a half times as much as someone with only a high school diploma. This benefit is self-evident just on the raw numbers, the greatest part of this is the fact that someone with a higher education will continue to get increased income, while someone without a degree will hit a "ceiling" on earnings. As someone grows older and builds a family this additional income is crucial for financial security.
As you see, getting a higher education is so much more than learning subject matter. The benefits of college education are so impactful they will be felt for the rest of a person's life.