Education is Slow and Shoddy

I think we do education all wrong in America.

I remember, as a young boy, getting the same lesson multiple times. I remember being so far ahead that I was in the top 3rd percentile. I remember doing decimal calculations 2 grades before being taught. I remember some teachers were very good indeed, encouraging the students under their tutelage to be the best people they could be. I also remember some teachers were power-tripping morons who apparently took the job because they got immense pleasure out of ordering small children around.
I've been in some kind of schooling since I was 4, and at least half of it was a complete waste of time. Now, the stated purpose of education is to prepare one with the facts and figures that one needs in postgraduate life. There is some liberal-arts that everyone is expected to know, and some specialty knowledge specific to your chosen field. You know the facts, you're ready to go.
Lots of time was lost to "discipline problems." Meaning that someone in the class would not STFU and the teacher had to stop and yell at them. Lots of time was lost to suddenly the professor just had to make a 30 minute rant about whatever was pissing him off that day. Lots of time was lost to circular questions in which neither student nor professor understood each other on any level.
I wonder if it is possible to complete secondary education (US grades 1 - 12) before one turns 12 years old. Currently, a 12th grade graduate is typically 18 years old. Would a longer day, or more intense instruction get it done faster? Or is brain maturity the bottleneck?
After all, I had classes up to my university sophmore (~14th grade) that were similar to my high school freshman (~9th grade) classes. Complete with the "CHRIST WHAT ARE YOU PEOPLE, FIVE?!?!" rants when the students would not STFU and listen.
Mostly I'm disturbed by pundit-articles that claim that the actual purpose of the upper-level of education is to keep teenagers off the street. If they get an actual education out of this, is a secondary concern. It scares me because I think it may have been true. I've spent 1/3rd of my predicted lifespan in school, and much of it was, for no good reason, effectively the same as a prison sentence.
Although on the other hand, these articles also proposed replacing high school with apprenticeships. This would not work in every field. Of my two hypothetical careers, one, system administration, would work well as a master-apprentice relationship. The other, computer programmer, would not. Programmers need more education, and if you handed me a 12 year old, yes, they could write code, but it would hurt my productivity because I would have to rewrite everything my apprentice did. I would have to rewrite it because it would be inefficient and incorrect. My hypothetical apprentice just wouldn't be educated enough to do the job right.
I confirmed this with a psychologist friend of mine. A psychologist would not benefit from an apprentice, who would just lack the education to do anything other than schedule appointments and play secretary. Unless the apprenticeship consisted mostly of the psychologist helping the apprentice with the apprentice's homework, but that doesn't exactly help the psychologist, does it?
I think as a society we should educate faster to increase our productivity, if at all physically possible.