And I find it odd that the objective criteria the author chooses ("it was not an objective collapse in living standards, employment prospects, or opportunities for material security.") are mostly not applicable to teens, but to adults.
And to the extent they are applicable to teens, well teen employment has dropped quite a bit since the Great Recession, and is just now returning to what is was in 2007: https://www.pewresearch.org/fact-tank/2022/06/21/after-dropp...
The percent of children living in "poverty" also increased by a few percentage points (about 1/4 to 1/3 in relative percent) after the Great Recession, and didn't fall back to trend until around 2017. This would have affected today's teens during formative times in their childhood: https://datacenter.kidscount.org/data/line/43-children-in-po...
This is not the claim.
The word “objective” does a lot of important heavy lifting here, and there are strong arguments to be made that subjective experience has gotten significantly worse, while most “objective” factors have continued to improve as the world modernizes.
The trouble is that evolutionary psychology is such that the major changes to how humans live and communicate leave us in an environment that looks less and less like the environment we evolved in.
This is why there is so much interest in the impact of social media. There is evidence that even among those who are in an objectively “good” circumstance when defining “good” based on safety, financial security and other commons measures, individuals are just as susceptible to the negativity and distorted reality that dominates modern social life.