I wouldn't come to conclusion so quickly; especially with the "complete and total absence of childhood" part. (Clearly it is not true, or we would all have committed suicide.) If you watch those TV dramas or movies from East Asia then you will realize we do have a lot of activities, sports and entertainment during our school years. Let me share you a little secret: girl dating game actually teach you more about Japanese education system than any western media source
As you point out, Finland has a very successful education system, with good grades and a more relaxed and happy learning environment. US education really cannot use the "we do not slave our children" as excuse for having bad results in global test ranking. (Yes, test result is not everything, but that's the most objective way when you need to compare among different countries.)
The fact that USA has more inventors and innovation (iPhones!!

) has a lot of causes outside education. First of all you must not be poor, you need to have spare time to think and be imaginative. If you work in a factory making iPhone everyday in China, you probably will not be the next Steve Jobs or Bill Gates. Secondly, in many countries, your invention will 100% be copied by your neighbor/friends/relatives/government/ random guy who saw your invention.
Another example will be myself: I studied in Hong Kong and travel to US to study for bachelor degree. My major was in physics and I simply cannot find school in East Asia that has the infrastructure to support my subject (nanotech center, particle accelerator nearby, telescope...etc). Hardware is a very important part in invention besides education.