1) You're right. College is increasingly becoming a less and less profitable investment. It's becoming more expensive and the benefits it affords you are diminishing. So, not going to college and just pursuing success out of high school is technically a better idea. However, it requires a lot of individual ambition, determination and work ethic which, let's face it, many people don't have. Plus, if it doesn't work out and you decide to go to college, it will be much harder to get in somewhere than if you applied right out of high school.
2) What is glossed over a lot in conversations like these is that if you do use college correctly, you really do learn things, things that are important and will increase your human capital—meaning basically that they make your brain better and more efficient, making you a better person and a better worker. If you're majoring in sociology and just doing the bare minimum to pass your classes, then maybe not. But if you're studying something even somewhat quantitative and you apply yourself, you can really learn a lot.
For example, I'm majoring in electronic music. Before you scoff at that, realize that being a music producer, an audio engineer, a sound designer for movies and commercials, a sound designer for theater, and a live sound engineer for concerts and shows requires a lot of specialized training, knowledge and experience. Yes, you can do it without a college degree. But being in my degree program, I have learned more than I ever could have possibly imagined, both about thinking creatively and expanding the ways in which I approach my work; and in direct, quantitative knowledge about working with all types of sound. I am nearly positive that had I not gone to this school and majored in what I'm majoring in, I never would have learned much of what I know now, and much of what I will learn in my next two years. I would have been, in short, far worse at what I do had I not gone to college.
So for me, college is a good investment. Yes, it's very expensive. And the degree doesn't matter much to me or to the field in which I want to be employed. But the knowledge and the experience I am gaining here will make me a vastly better candidate for employment, which will allow me access to better jobs faster and will hopefully help me climb the ladder of employment faster. It could also set me a notch above other applicants for jobs.
3) Facilities: this only matters for some majors, but things like recording studios, research laboratories, machine shops, etcetera are available for use for no extra charge at colleges. I have access here to two full-featured recording studios that I can use for whatever purposes I need. That is huge for me. Experience working in a real recording studio is invaluable in the audio industry. Similarly, science majors need labs to conduct research, and so on.
4) Networking: this is used as a cop-out argument a lot, but truly, going to a school means you gain access to a network of students who will one day be alums in the real world. You will make friends who will go on to (hopefully) do real things, and you will have an instant camaraderie with other alums of your school, even if they have never met you. They will be more inclined to help you out. This mutualistically beneficial web of connections is helpful, especially in a down market where there are scores of overqualified workers gunning for the same job.
So, those are some of the reasons.
