You mention healthcare twice. Let's think about this.

The poorest US state is Mississippi, and its life expectancy is an outlier -- far below the national average and half a year shorter than any other state. Yet the average Mississippi lifespan of ~73.38 years (in 2021) is nevertheless substantially higher than the life expectancy in Greenland.

Also: The colony of American Samoa, despite having some of the heaviest people on Earth, has a substantially better life expectancy than Greenland.

So maybe you guys have good healthcare in Denmark, but the inhabitants of Greenland clearly aren't benefitting from it. This, again, speaks to bad stewardship.

Could it be that a lot of the inhabitants are Inuit? I could imagine they refuse modern health care, similar to Amish people in the US? A quick google search shows an average life expectancy for Amish people to be 71.

I might check those hypotheses later.