Canada is population dense in the parts where people actually live. For most people who live in Canada, the population density they're used to is in the hundreds or even thousands per square kilometer, which is right on par for Europe.
Population density is an extremely misleading statistic because it doesn't tell you for how much of the population that data is representative. The number is only so low because the uninhabited parts of Canada really are that big.
Depends on how you look at the stats, if you are just looking at the singular population density for the entire country, and how that affects the spread within major cities, then yes it can be misleading (even if not entirely insignificant), but if you are looking at it in the ways that the size of the country manifest itself in the spread between different areas, it makes a very sizeable difference, especially given that countries will react base on the number of cases that showed up in their respective country, and not on how spread out through the country it is.
The distance between Vancouver and Toronto alone is about the same as from Portugal to Finland, aka from one side of the EU to the other, and the population between those 2 points is many times bigger inside the EU than it is in Canada, all the while the EU having quite significantly better public transportation to allow movement in mass between its areas, while Canada, having been there, let us just say it doesn't really compare.
Spain alone has significantly more people than the entirety of Canada despite being a much smaller area, and ofc this doesn't manifest itself only on the distance between major cities, which in itself has a major impact, but it also manifests itself in the very distance between houses and buildings, Canada houses are on average about double the square footage as they are in Spain or the United Kingdom, and business establishments also tend to be much larger, with much larger parking lots, making for much greater distances.
For example looking at what is one of the worst case scenarios of Canada city wise and comparing it to Spain, we have Toronto with a population of 3 million people, and Montreal at 550km apart with a population of 1.8 million, in Spain on the other hand we have Madrid with a population of 6.6 million with Barcelona at 625km with a population of 5.5 million, which even when adjusting for the population difference between countries that is several time more people in proximity to one another. Also, I really cannot stress how much better the means of transportation between these the EU cities are, I have been in the 4 cities mentioned above, and yeah while modes of transportation within the city one can make an argument in favor of each (kind of sort of but not really), between cities we aren't even playing in the same league.
As I said in my other post, Canada was always going to do "well" in this, short of some absolutely epic failure on the government part, its geography is borderline unparalleled in how good it is for this kind of situation.