That’s a lot of people. Where are all those people going to be housed? Where will the resources for their education and gainful employment come from? Is the Canadian job market exploding with a huge amount of well paying jobs such that Canada’s children have multiple options to pick from, or will everyone be competing for scraps?
So I don’t know how much you know about economics but it’s well known that gaining an increased population of working aged adults is actually pretty good for the economy, because they generate demand (create jobs) and then also take up jobs (generate supply). Immigrants are more likely to be entrepreneurs and statistically consume less social services.
