Inhowfar is Finlands demography special? Looks pretty standard to me:
Which country are you from?
As for Singapore: they do pretty well in recent years and with quite a different schooling system. I am against standardized tests though, this does not help students to think but instead to follow rules and predetermined routine. Makes for good workers, but bad innovators.
As I said, I was from GDR, which had a school system which generally was seen as doing pretty well and which also had no standardized tests. As far as I know germany as a whole has no standardized testing routine in school to this day and does overall not too bad (better as the US in any case).
Well for one thing Finland seems to have an abnormally low student to teacher ratio so comparisons can be distorted with other countries and they have a very strong teacher's union. No other nations or administrations with just as successful and competitive educational systems can replicate Finland's model such as Canada, Singapore, Japan, Hong Kong and South Korea so Finland should be rightly treated as an anomaly to be ignored because there's nearly nothing of value to learn from the case ...
I'll let entertain which country I'm from as the one's I've listed from the above aside from Finland is the other oddball out among them ... (even I think our system might be distorted as well because of a high amount of rich immigrant expats)
As for Singapore, yes they do very well and are nearly diametric opposites to Finland's model. As for standardized testing, there is one very big advantage that it does grant which is a competitive environment against other students because without a benchmark to provide some sort of measure of ability among students there is no realistic way for them to self motivate themselves to improve. I can possibly understand why you might object to standardized testing but when it comes post-secondary school admission then the only truly fair and just way to benchmark students with varying secondary education quality on equal grounds is with exams. I can get why you oppose standardized testing so much but when prestigious schools have limited seats and students with very different previous educational backgrounds then it must become a necessity to settle it with a standardized test especially with very big countries like the US or China ...
There's more to an educational system than just purely increasing the quality like we see with Finland but a lacking component keeping it from creating the truly best students like we see with either Singapore or Hong Kong is facing the competition. While Finland can pride itself as having the most arguably pleasant educational experience with great results, they cannot pride themselves as either having the best students or being a role model for other countries ...