1. Canada is not empty. In fact Canada is quite full, as the comfortably habitable area of Canada is more akin to the total area of say Poland, or Spain - countries with fewer than 50 million people.

2. This coincides with the population of all the US states that border Canada - around 50 million people, although in at least two cases - New York, and Minnesota, the bulk of the population is as far from the Canadian border as possible..This is because (climatically, at least) the "best" areas of Canada = the "worst" areas of the USA.

3. Several studies from Sweden and Switzerland indicate that there is no need for a constantly growing population to maintain a standard of living. 

4. Japan is showing that an aging population is no issue either. What is eventide from Japan as it ages is just that - lifespan in increasing. That is not a sign of a struggling country.

Young countries are vibrant.  But at the expense of the youth being dissimilar to the existing population?