Knowledge can be put to use in many ways. However, too many people these days erroneously think college should train you to step onto some preprogrammed career path. Never did, never will. College is supposed to teach you to think, to analyze, and bring greater understanding of aspects of the world to your life as well as your livelihood. Learn those, and you can create your own career path.
Now that the world is moving into the Post-Jobs Era, where already 35% of US workers are self-employed, college is more important than ever. And not some canned program like accounting with remote control career path, and no broader skills, greater brain power. In fact, accounting is being automated rapidly, and accounting jobs are increasingly competitive as they will grow increasingly scarce. You have to create your own career path. And you'd better not dismiss broadly based education, creativity, etc, or you can be replaced by a computer.