My nieces went to public school in central Toronto. I was not impressed with their education. Their neighborhood, and hence their school, was very culturally and economically diverse. Lots of UT faculty and administration families (including them), lots of immigrants. They both did French Immersion, which probably worked somewhat the way @gwnorth described. But what it didn’t do was teach them French, or do a very good job teaching them anything else. I remember being pretty scandalized at their poor reading skills around 4th grade.
By high school, they had great grades and were at the top of their class, but they were very nonacademic, and had pretty limited academic ambitions. One went to McGill, but disliked it and wound up transferring to Western for a variety of reasons, chief among them a boyfriend and membership in a circus troupe in Toronto that actually produced meaningful income. The other went to Toronto and did fine, followed by a semi-professional masters at McGill. The second one actually did her last semester of high school at a school in a wealthy neighborhood, and she was shocked at how different the classes and the students were, how much more competitive, fast-paced, driven.
It’s funny: I am very close to both of them and to their parents. I love all of them to death. They are wonderful people. But I have never discussed their education with them or with their parents. It feels like a little bit of a third rail. Their mother is a world-class academic, someone who receives a major honor every other year or so, their father a very blue-collar refrigeration systems tech. Both parents are very proud of how egalitarian the Canadian system is, but I know their mother has to have had a tough time with their non/anti-intellectualism and middling ambition.