...even if you never actually work in that field.

It allows you to know about at least one discipline at a deeper level than most people do. So even if you never work as, say, an astronomer, you at least get an idea of what's involved in astronomy, how its related to other fields, and how it fits in with the totality of human knowledge, history and culture. You also pick up information on related areas, like physics, chemistry, math, programming, and some of the engineering involved in astronomical technology.

When I started working with remotely sensed satellite imagery for the exploration department of an oil company, I found that my knowledge of imagery, spectroscopy, optics, orbital mechanics, sensor technology, atmospheric physics, was invaluable. The geochemists I was working with, who were specialists in the infrared spectra of minerals, were usually working with programmers who often had no idea just what a spectrum was! They found out that at last there was a programmer who could understand what they were saying, and what they wanted the code they were requesting was supposed to calculate.

Another advantage of having at least a basic grounding in a specific field is that you realize how much there is to learn in any other specialty you may encounter. You suddenly grasp that ALL fields are like that, filled with mysteries, unplumbed depths. Even if you don't know as much about geochemistry as you do about astronomy, you appreciate that geochemistry is just as deep and vast a discipline as astronomy is.

And I was further blessed with attending an institution of higher education that gave you a basic grounding, through elective courses, of the humanities, foreign languages, the behavioral and social sciences, and other fields outside your own major. You are taught critical thinking, and how to express yourself in writing. And of course, you were exposed socially to, and interacted constantly with, students and teachers in those fields and the issues they were concerned with, that were of vital importance to them.

Its not the University of South Florida's fault that I never became a successful and productive astronomer, but I believe it did an outstanding job of making me a better citizen and a well-rounded and educated human being.

You can do all this without going to college, of course, but its harder, especially for a young person suddenly facing the crises and distractions of suddenly being on their own in a complex and mystifying world. The University system of higher education was first introduced in Medieval times. It has turned to be one of the most valuable cultural achievements of Western Man. It is NOT a trade school designed to grind out mindless corporate worker bees, or a means of generating sports journalists, event planners, rock critics and real estate investment counselors.