It takes a long time to build up the infrastructure that you need in a country - it's one thing to have excellent education offerings, but you also need all the other parts to make it translate into an effective business environment. You need a legal system that is fair and reliable. You need a police force that has ideally no corruption within it at any level. You need relatively stable governments that do not make rash or unexpected decisions to undermine confidence. You also need a central bank that can act independently and will not succumb to outside pressure. All of these are needed in order for a successful education system to flourish and provide great students.
It is extremely essential for a government to produce quality students equipped with various skills that would bring them success but quality students are nothing but students until they are thrown into real life or outside of school. Yes, you learn a lot from institutions but an economic system would function at its peak effectiveness if there were also job opportunities for said students.
Many countries have outstanding students but end up leaving the country due to the lack of opportunities for them. They are developing themselves only for other countries to benefit off of. It all has to be in balance.