We now take it for granted that people are paid to teach in schools in universities, but such has not always been the case, and it is a system hard to justify on logical grounds. The biggest problem with the idea is that a professional teacher is unlikely to be as skilled or knowlegable on a subject as someone who practices it for a living. This is an ongoing cause for concern in all areas of work that require practical skills. Even though students go to college to be trained as cooks, car mechanics, builders, hairdressers, etc., it is accepted that they have to have work experience, working in real businesses before they can really learn the trade.
The reason why tradespeople do not take on apprentices, like they used to in the old days, is not so much because they are incapable of training a young person to do a particular job, it is more because it is no longer worth their while to do so. On the one hand, businesses are under pressure to make short-term profits, and cannot afford to make long-term investments in training staff, and on the other hand, there is no guarantee that an apprentice, once trained, will stay with the company. As a result, people settle for the system of students being prepared for work in a non-working environment by people who are not subject to proper business pressures, and who have only limited experience of a business environment.
Unsatisfactory though this may be, it is not as potentially damaging as the system of employing professional teachers in theoretical and academic subjects. At least there is a certain amount of communication between businesses and training colleges, and teachers have to accept feedback from local employers about the quality of their work. In the academic sphere there are almost no external sources of feedback or control.
Some subjects, most notably history, but also literature, philosophy, political science, and, to a certain extent, economics, are taught with a strong local bias, with different countries teaching different interpretations of the same facts, and students being assessed on how well they are able to conform to the local perspective. Different institutions may also wish to promote their own view of key events, so that students that attend one university may be expected to espouse a set of right-wing beliefs, and students that attend another, left-wing beliefs. At one time, scientific subjects were thought to have been immune from this form of institutional bias, but the role of business in funding scientific research has forced different universities to take a stand for or against specific technologies; and now that climate change and the environment have become such emotive issues, scientists have divided along political, economic and ideological grounds for and against various policy initiatives and new technologies, leaving little room for logic and clear thinking.
The education system is set up in such a way that, generally, the people who go into pre-school child care, did not themselves do very well at school and have very few academic qualifications, the people who become primary-school teachers did slightly better, but were not academically successful; secondary school teachers generally have a university degree in the subject that they teach but did not a particularly good one, and then some of the most successful students stay on and teach in a university. This means that when you are very young, and most able to learn, you will be being taught by people who have the least grasp on their subject matter. As you progress through the system, you will be asked to forget much of what you were told by them, because it was either over-simplified, or simply invented. Naturally, most children find this to be very disorienting, and become increasingly confused as they progress through the system. Ultimately it leads to a class of teachers who are not properly interested in the material that they are teaching, and who do not really believe that it has genuine value.
The way to foster learning is to allow children, and young people, to develop an interest in a subject, and an awareness of its significance, and for them to be able to seek out someone who can help them to find out more about it. This would involve children feeling part of a wider community, so that they would know directly, or indirectly, adults who had a wide range of skills and interests. The real repository of knowledge in our society lies within people who have spent their lives working in a particular trade or profession, and it is perverse that they should not be able to pass on their knowledge and experience to the next generation.
By leaving education in the hands of professional teachers, people deny themselves the chance to pass on to children the knowlege that they have acquired in their lifetimes, and it allows what people are actually experiencing in their daily lives to become increasingly disconnected from what children are being taught to expect during their years in school.