Okay, I can introduce you to three real world alternatives I've seen in my own life—self study, direct mentorship and work experience. I'll share one example of each from different fields.
To be clear, I don't think there's a single one-size fits all solution for education. One of the core problems I see in formalized schooling is that by its nature it pushes large numbers of people through the same curricula. This may have been good in the early industrial era, but in today's world most job-related skills that can be commoditized are either outsourced or automated. Non-job related skills are also of great value, though it's not clear that it's best for people to build them in an factory-line style either.
Self-study: I put over a thousand hours into foreign language classes while growing up and got pretty bad results. It's an ancient discipline and curricula have had centuries to adapt, but it's just not well-suited to formalized schooling. I've met literally thousands of people with advanced degrees in English language study who don't speak that well. I've also met a lot of foreigners who graduated with degrees in Chinese who don't really speak or read comfortably. Though I've hired people for positions in which English language skills were important, I've never even considered looking at their related credentials rather than evaluating their results. Foreign languages are very learnable through self-directed study. This is even true for one's native tongue—most really good writers have gotten there through voracious reading and practicing their craft, not generallythrough advanced degrees.
Work experience: Another discipline I've seen schooling fall down is in sales. It's a core business skill, but those I've met who have excelled in it have come from a variety of backgrounds, not necessarily business schools. Almost invariably, the people who really know how to sell have gotten that way through work experience, either for themselves or on commission for someone else.
The third alternative, that of direct mentorship, is probably the most powerful I've encountered. Especially in music, athletics or other extremely competitive fields, there's nearly always a mentor behind the top performer, and often there is a series of several mentors over different stages of the learning process.
Now at this point, I suspect you're thinking about the fact that there are two types of educational goals—getting really good at something and getting to minimum level in all the core skills. Though my three examples were related to the first goal, schooling often fails in the second goal as well. It can succeed, but there are still a lot of people who do what must be done to get the credential they want and little else. On the other hand, it's exceedingly rare to meet someone who reads broadly and doesn't end up with at least a decent education.