I find it amazing that all those English-speaking experts who keep visiting Finland to find out why its children outperform other countries miss the obvious reason: Finland has the most learner-friendly spelling system in Europe.
We know children who become enthusiastic readers at a young age become good learners in general. Finnish children reach adult reading proficiency in months, in sharp contrast to the one in five English speakers who are still nowhere near that level after six years at school.
The fact that Finnish spelling is phonetic makes reading failure rare. It also frees up oodles of time for learning useful things, instead of wasting it on making sense of contradictory spellings such as "our - your", or "man - many" and trying to memorise them. This is taxing and tedious.
The Finns made their spelling learner-friendly because they began to value mass education more than five centuries ago. In England there were still battles to preserve mass ignorance as recently as the 1870 Education Act.
If English-speaking elites really wanted more people to learn to read and write, they would not tolerate identical spellings for different sounds (read today, read yesterday) and different spellings for identical sounds (leave, sleeve, grieve, eve).
Author of 'Understanding English Spelling'
24 Filleul RoadWareham, Dorset