The downtown core of Charlottetown is as dense as Sidney or Esquimalt, it is just that the planners built a lot of greenspace into their city design...
I don't mean to give you a hard time but I'm reminded of a Halifax forumer on another board who always says things like this whenever people compare density between Canadian cities, as if only cities in Atlantic Canada contain parks, industry, and other non-residential uses. Esquimalt and Sidney both contain green space, not to mention a wide range of other uses: commercial, recreational, institutional, and otherwise. All places do.
Just look at the numbers. Esquimalt has half the population of Charlottetown but in less than one-sixth of the land area. Is there no green space in Esquimalt? No shopping centers, parking lots, schools, industrial properties, etc.? Of course these things are there. These things are everywhere.
I've never been to Charlottetown but let's play ball here and suppose that half (!) of Charlottetown city's land area is empty green space, and let's also suppose that there isn't any green space or other non-residential uses worthy of note in Esquimalt. Even if the populated area of Charlottetown was only 22 square km, the average density per square km within that populated area would still be well below Esquimalt. You'd need to reduce the land area of Charlottetown city by two-thirds to get the same average density as Esquimalt. That would be a heck of a one-sided adjustment.
How about Oak Bay? Would we say a lot green space has been incorporated into Oak Bay's design? Oak Bay's density is double the density of Charlottetown city.
How about Saanich? Saanich is big (2.4x the land area of Charlottetown city) and Saanich is overflowing with green space. But Saanich's density is still more than 30% higher than Charlottetown city.
Anyway, I'm always curious about this sort of thing so when I have time later I'll have a look at the census dissemination areas. Maybe Charlottetown does indeed have some very dense neighbourhoods that balance out the unpopulated emptiness? But the aerial pics suggest otherwise.