Really the only effective way for non-native French speakers in Canada to become fluent without moving to a French only language community is via early French Immersion programs. The regular French program does not result in fluency without significant external tutoring and the majority of students in Canada do not attend French Immersion programs.
Even in Montreal that’s often only the norm for Francophones, due to the dominance of English in the rest of Canada and the world. The minority Anglophone population in Montreal tend not to speak French. I have a good friend who was born and grew up in Montreal in a Greek family and while she has some French facility she’ll be the first to say that she isn’t fluent in French (or Greek for that matter). Her husband who immigrated from Greece to Montreal in his teens is bilingual in Greek and English, but he doesn’t speak French either.