You are correct decentralization is key, but not sufficient.
I think it must begin with federated data systems under local control.
Then with emerging technologies around credentialing, the open badges standards, and block chain we create a system of inter operability that gives credit to both in school and out of school activities.
Finally we empower students to reshape local schools by getting more involved in governance and making membership in extracurricular activities less extra and more part of the culture.
An explosion of amazing learning and agile community tools have developed in the last thirty years… unfortunately schools have not been one of them.