How can you teach a subject if half the time you truly don't understand what it is you're are saying? Like for example a Math teacher should have to get a math degree in order to teach, because that shows that they know what's going on and know how to interpret things to the students. Teachers only have to have an education degree which is dumb because anyone can get one. If you're a teacher with an education degree the people that rank over you literally just give you a sheet of paper and it says what to do. As for someone with a degree specifically in the subject you're teaching it gives the kids more understanding than something read off a page.
Yes, teachers should have to work in their field before teaching, because a student should have a teacher with some life experience. Teachers that do not have any real-world experience, for example law professors, are often out of touch with the demands of the real world. Without knowledge, they cannot be effective teachers.
The only way teachers can truly learn and gain experience is by teaching. By working in their field before they are allowed to teach, they are limited in the amount of experience they can gain. I think teachers should start as student and substitute teachers and move on from there.