The article has a paywall for me and I was curious about their methodology. Fortunately, Wikipedia has some information:

"Nationally representative samples of respondents are asked to think of a ladder, with the best possible life for them being a 10, and the worst possible life being a 0. They are then asked to rate their own current lives on that 0 to 10 scale."

https://en.wikipedia.org/wiki/World_Happiness_Report

It could be named the "lack of ambition" report.

Or equally lack of envy or discontent.