There are several reasons why Finland's education system is rapidly going down-hill. If you are interested, I have been exploring these, and what we can do about them, in a book called "Education Unchained".
(1) The first reason is confusing a tool, school, with what one is trying to achieve, education.
(2) Gemeenschappelijke lagere cyclus (comprehensief onderwijs)
Secondly, the obsession with providing "everyone" with the same education. This should be an absurdity in any country. There are tens of thousands of professions in a modern society.
The combination of the two is commonly to force everyone to attend the same schools, together for 12 years. (in lagere cyclus s.o.)
(3) Modieuze didactische aanpakken
Thirdly, abandoning traditional teaching methods. The "art of teaching" goes back to ancient Greece. Over the past century one has attempted to replace this art with one academic fad after another.
The result of all this is an absolute disaster. In my native Sweden, up until 1968, about a third of students exited the system at 19 knowing Swedish, English, French and German. Those who studied vocational subjects became consummate professionals at the age of 16-17. Today, beginning students at medical school fail exams because their Swedish is too poor.
(5)Alle leerlingen zijn de dupe, maar nog het meest de zwakkere leerlingen
It is true that the modern school systems serve those who are academically gifted badly. Since 1968 they have probably lost at least half of the education they used to receive.
But the disaster is even greater for those who struggle with academic subjects. A substantial minority, maybe a quarter, learn nothing at all, in school, between the ages of 12 and 19.
(6)Besluit: Finland gaat Zweden achterna
Finland today is in the midst of committing the same mistakes that Sweden made rather abruptly in 1968, and that the US made during the course of the 20th century.
There are solutions to this, that can quickly be implemented, but they require that we radically change the ways we think about education.mmm