Going off Wikipedia, I mean as a methodology that develops rational thought and intellectual capabilities through multiple fields of the study, as opposed to vocational, professional, and technical schools.
My experience in pre-secondary school public education, though admittedly not what most Americans would consider a gold standard, leaves me highly unconvinced of its cost-effectiveness.
Trying to teach students what they don’t want to learn is like Sisyphus rolling the boulder up the hill, and my experience suggests students don’t want to learn the majority of what they are taught. Once someone is introduced to a field of study through a class, retaining adequate knowledge of it requires continual study, and application of theories to real events.
Even A-students usually limit themselves to memorizing material for tests and papers, forgetting about it afterwards. I could ring up my brother, who was Valedictorian and had a very good understanding of mathematics up through Calculus, and drill him about questions on that and other subjects he aced back in the day. Very likely I would receive bemused silence in return. He is not the only successful student who would have such a response.
The basic goal of education should be to transform adolescents into (1) good citizens who can understand and maintain a democratic-republic, (2) productive members of society who can manage their own households, (3) practitioners of humanist morals and habits who are active in their communities; the sorts of things American society desperately needs to survive and flourish and which education is not providing.
Traditionally it is believed the best chance for those things arises from general study offered through the liberal arts, but I think we can develop enough awareness of the limitations of the adolescent mind and our current education system to develop a vocationally-centered system that can direct the youth to the occupations listed above from toddler years to young adulthood.
Of my own experiences I consider most vital to my belief in this theory, they can be summed up in the role geography has played in my intellectual life: at the time I studied it in high school, I had no sense of the purpose behind the class and proceeded through it much in the manner of the A-students listed above (though I think I got a B). It was sometimes enjoyable while I took it, but it didn’t distill much lasting knowledge for the reasons listed above. Later on, I developed a limited (though useful) understanding of geography through independent liberal arts study (particularly the histories of the Ancient Greeks/Romans/Neoclassical texts, and some contemporary scholarship focusing in different historical periods around the globe) and truth be told the Total War series of video games (modified versions of which I believe ought to be utilized in geographic-historical studies wherever applicable).
That knowledge has helped me a great deal in understanding contemporary international relations as they are transmitted through news media, but the fact is it developed as an accessory to a field of study I had a great deal of personal interest in, and very little of it can be traced to the class of geography itself.
Some people would contend something valuable has been lost in emphasizing such practical knowledge over general academic pursuit, but since our current system fails to distill either appreciation or lasting knowledge of academics, I would argue that nothing has been lost and something very valuable could be gained from a reform designed more to appeal to experience and to develop usefulness.
Above all else, I don't want students to lose sight of the purpose of what they study and its relevancy to their own life and experiences. That's the beginning of the end for any form of knowledge.