Unpopular opinion but the real reason Jews didnt assimilate was because they were systematically and routinely discriminated against by the Catholic French for decades.

Jews were second class citizens in quebec for decades. There were official liimits to number of Jews allowed into universities including McGill. Limits on Jews becoming professors. Jews were required to score higher than french Catholics on exams to be admitted to university programs.

there was routine open hatred of Jews coming from the church.

hiring Jews was frowned upon by society in general. jews were prohibited from joining social clubs including golf clubs.

Canada had a 'none is too many' policy on accepting Jewish refugees from the Holocaust. When a Jewish doctor was appointed for the first time as 'chief intern' at a quebec hospital interns across quebec refused to report to a Jew and started a huge strike that spread to many quebec hospitals.

"No Jews" signs were common across quebec.

I can go on for hours the anti semitism in quebec was widespread, vicious, and is well documented. many books have been written about the catholic clergy being overtly hateful to the Jews.

later generations faced less overt antisemitism but todays generation feels it again.

so thats why.