I have found that young adults who are in an environment similar to those of the "Gen x/y Finnish" have similar traits. However, the United States does not have the luxury of having nearly the entire country living an environment like that (compared to the relativity small and highly metropolitan European countries).
To draw a comparison in the way you have is disingenuous.
I'm just as suspicious of Scandinavian comparisons as the next American, but this is not a valid objection. We are specifically comparing the privileges and services that each society provides to its citizens, for the citizens' well-being and that of the society as a whole. To say, "we don't have that luxury" (of what? a "metropolitan" environment? our urban kids do worse than our rural kids!) is to admit in damning fashion that our privileges and services aren't as good as those the Finnish receive. I could understand this sort of whining from Bangladesh or the Congo, but coming from the USA it's pathetic.
It's a lot easier for 17 million people to live in (relative) privilege than it is for 300+ million. Scale matters when dealing with tangible requirements.
I'm not sure what "scale" is supposed to indicate in this context; if you rank nations by population density then Singapore is at one end and Finland is at the other, and they both have better results than the USA. In 2011 Finnish per capita GDP was less than 80% of ours. I don't doubt they'll pass us eventually (Singapore already has), and our woeful system of elementary and secondary education is a principal reason why.
That's like saying the elites in [insert third world country] who go to western-style universities are quite similar to their western counterparts, and therefore it's disingenuous to talk about the conditions most in that country live in.
To draw a comparison in the way you have is disingenuous.