Education is extremely political. It's not that we can't come up with better ways of occupying school-age children. Montessori has been around since the early 1900s! The problem is convincing everyone they need to adopt a new method. Which is absolutely completely politically impossible compared to making small tweaks to the system already present. Nobody is going to turn education upside down. Ever.
At least, that's the situation in Germany: There are Montessori schools, Waldorf (Rudolf Steiner) schools and various others. The thing is, most of these schools have a foundation in bullshit theories or religion. I think the fact that children have to start each day with prayer at the school in question needs to be highlighted more.
The comparably good results could equally-well be explained with the fact that the pupils at these schools are predominantly from well-to-do or at least education-oriented families. Neither the teachers nor the pupils face the same socio-economic pressures as they would in the public school system.