You touch on a point inadvertently about what makes immigration so beneficial is that the workers can start working as soon as they arrive. Or at least, as soon as their qualifications are transferred over (for example nursing). Which is far quicker than having someone born in Canada and waiting 20 odd years til they enter the workforce.
So, theoretically, the new people can help build homes, hospitals, schools, etc for the other people who need it, and then the new new people will build for the new people, and etc. There just doesn’t seem to be much planning going into it besides bring people in to make numbers go up. Also, major infrastructure works take years, so they’ll never be able to keep up.