As well as it may have worked for you, for most, it won't end as well. I also agree that even college is slow paced for learning, but not everyone can learn really fast in all subjects. My upper level classes had quite a quicker pace than the lower level, but most of the "baddies" were weeded out by Jr year.
I would argue that I learned more in my Generals than my Major. They strengthened my critical thinking quite a bit. I'm used to doing critical thinking and research on computers, but I'm good at computers and have a lot of knowledge. Doing critical thinking and research on subjects that I have less knowledge and experience is COMPLETELY different. The most important thing you'll learn is "what you don't know".
When someone doesn't know that they don't know something, it's like a "null" value. Their brain doesn't know how to handle it and assumes they do know it by thinking it's something they already know. False positives.
Couple that with having whole-class discussions about different points of view, pros and cons of those views, and the reasoning being those views. You learn a lot about learning.
4 year Uni greatly increased my critical thinking to the point that the knowledge acquired was almost worthless. But if you talk to any of my teachers, that's what their goal is. So many after-class chit-chats with a wide range of teachers. All very nice people.
Anyone can acquire knowledge, anyone can acquire experience, but the most important thing you get some a good University is neither of those and is more important.