I knew some fellow who graduated as an engineer. He’d worked summers at the local small town main employer, and in the process had pissed off some boss there so could not get hired when he graduated. The employer had seconded one of their technicians to teach some practical industrial course at the local high school… until the teachers’ union discovered the guy had never graduated high school. At that point this brand new engineer got the chance to teach. Then the teacher’s union got involved again, and he was allowed to continue on the condition he get a Community College teaching certificate. He did this over the summers in a remote big city - and being the “I don’t care” type he was, he stayed at a skid row hotel while taking the course, pointing out how much cheaper it was than any other temporary accommodation. And going forward, as a teacher with a BSc degree, he pointedly told the guys he would have been working with that teaching paid more than their engineering jobs at the plant.
This would have been over 35 years ago. In the last few decades, the school board won’t look at anyone without a bachelor degree in education for a permanent teaching position, and that goes for almost anywhere across Canada.
I recall reading someone’s reminiscences about growing up in Quebec in the early 1900’s, who mentioned that some teachers didn’t know much but were hired anyway. His favourite was some guy fresh off the boat from Paris - supposedly that fact appealed to the local school board but the bonus was the guy knew no English, so they skipped the English lessons.