Europe has another problem. They have a much more hostile relationship with their immigrants. Most of their muslim immigrants arrived as "guest workers" and were never really welcomed there. Most Europeans perceive that they have somehow overstayed their welcome and slipped in through loopholes.
By contrast in Canada and the USA our immigrants were far more welcome here, were given a clear path to full citizenship on arrival, and generally encouraged to see themselves as equal partners in the Canadian or American experiment. Canada takes a multicultural approach, while the US expects much more integration, but both nations expect immigrants to join the country as equals, which is a different attitude than the "guest workers who somehow managed to stay" approach that Europe took. Now there's discrimination for sure, but overall, we welcome immigrants in a way that Europe does not, and as a result have a much more amicable relationship with our immigrants.
So, even the immigrants they DO have tend to have a far more hostile relationship with the state, whereas in Canada and in the USA there's far less tension like that. This is why even though we have higher rates of immigration, per capita, we don't have the sorts of race riots that plague Paris, and the associated poverty that goes with ghettoizing former "guest workers".
Overall I think those extra social tensions in Europe mean they get less benefit to their economy from the immigrants that they do have, than either Canada or the US (or to be fair, than Australia/NZ either.)