That is an extremely misleading statement. Approximately 75% of Canada's population lives within 150km of the US border, and even that is not a uniform distribution , there are dense urban population clusters.
Around 30% of the total Canadian population is in the Greater Toronto Area, and if you toss in the most populous Quebecois (Montreal-Trois-Rivieres-Quebec) cities that number is around 50%.[1]
You see the same thing in the US and Australia as well -- the Eastern coasts were settled first, and that's where the population is to this day.[2]
[1] https://en.wikipedia.org/wiki/Population_of_Canada_by_provin... [2] https://en.wikipedia.org/wiki/Northeast_megalopolis
And then there's the geography. You can drive to each major point in California in a couple hours, but it's not as easy to get to Moose Factory or Fort Mac, let alone lay the backhaul to supply the towers in the middle of absolutely nowhere.