It's like using Canadian population density with the whole country when almost the entire population lives within a hundred miles of the US border.
You've never been to Stockholm metro area. It's very sparsely populated compared to many big metro areas.
Stockholm is a small city (800k people or so) surrounded by villages (another 1.5 million people) spread over 6,519.3 km2. Density is 360/km2
And that's the biggest city in the country.
In comparison, Paris (as we were talking about France): 13 mln people over 18,940.7 km2 with a density of 690/km2. That's for metro area. Urban area alone is 10 mln people with density of 21,000/km2
Which is why Tegnell had the gall to blame immigrants for the spread of Covid-19. Immigrants live in more densely populated areas.
And all this still doesn't explane a significantly larger mortality rate than immediate neighbors that have similar populations.