The ones who are currently teaching the kids right now?
Also, varies by country: the second world has "pedagogical universities/colleges" which are focused on producing school-level teachers in every subject taught in the schools — maths, chemistry, CS, you name it... and usually they have the lowest requirements compared to any other universities, so people apply there for a "last resort higher education" so to speak.
And then some people are bright enough to do well there, and some are not quite, and after graduation the smarter ones generally manage to find a better job than to be a school teacher while the dumber ones, well, they apply to schools to teach. And they get employed because schools almost always lack teachers. Yay...
Also, varies by country: the second world has "pedagogical universities/colleges" which are focused on producing school-level teachers in every subject taught in the schools — maths, chemistry, CS, you name it... and usually they have the lowest requirements compared to any other universities, so people apply there for a "last resort higher education" so to speak.
And then some people are bright enough to do well there, and some are not quite, and after graduation the smarter ones generally manage to find a better job than to be a school teacher while the dumber ones, well, they apply to schools to teach. And they get employed because schools almost always lack teachers. Yay...
I imagine things are better in the first world.