Education may be all about signaling, but I haven't found another job whose primary responsibilities consist of taking mostly interesting classes in a wide range of disciplines for four years. And while corporate campuses may aspire to be like college campuses, most of them aren't nearly as nice, as social, or as enjoyable. Colleges also tend to have superior libraries, art galleries, sport/recreation facilities, and performing arts venues, and they provide a vast array of extracurricular activities and clubs.
Working is financially a lot better than taking out massive student loans, but it usually doesn't give you a lot of time to study random subjects that interest you, or to pursue fun and educational activities that aren't related to the company's core business.